diff --git a/abonapp/models.py b/abonapp/models.py
index 1862b24..5a19756 100644
--- a/abonapp/models.py
+++ b/abonapp/models.py
@@ -162,7 +162,7 @@ class Abon(BaseAccount):
         Return icon list of set flags from self.markers
         :return: ['m-icon-donkey', 'm-icon-tv', ...]
         """
-        return ["m-%s" % name for name, state in self.markers if state]
+        return tuple("m-%s" % name for name, state in self.markers if state)
 
     def is_markers_empty(self):
         return int(self.markers) == 0
diff --git a/abonapp/templates/abonapp/peoples.html b/abonapp/templates/abonapp/peoples.html
index 1e923a7..354305f 100644
--- a/abonapp/templates/abonapp/peoples.html
+++ b/abonapp/templates/abonapp/peoples.html
@@ -10,6 +10,8 @@
     </ol>
 {% endblock %}
 
+{% block page-header %}{{ group.title }}{% endblock %}
+
 {% block main %}
     <div class="row">
         <div class="col-lg-10 col-md-8">
diff --git a/abonapp/views.py b/abonapp/views.py
index 51a5b16..b4a9bf9 100644
--- a/abonapp/views.py
+++ b/abonapp/views.py
@@ -30,16 +30,11 @@ from guardian.shortcuts import get_objects_for_user, assign_perm
 from guardian.decorators import permission_required_or_403 as permission_required
 from djing import ping
 from djing import lib
-from djing.global_base_views import OrderingMixin, BaseListWithFiltering, SecureApiView
-
-
-class BaseAbonListView(OrderingMixin, BaseListWithFiltering):
-    paginate_by = getattr(settings, 'PAGINATION_ITEMS_PER_PAGE', 10)
-    http_method_names = ('get',)
+from djing.global_base_views import BaseOrderedFilteringList, SecureApiView
 
 
 @method_decorator((login_required, lib.decorators.only_admins), name='dispatch')
-class PeoplesListView(BaseAbonListView):
+class PeoplesListView(BaseOrderedFilteringList):
     context_object_name = 'peoples'
     template_name = 'abonapp/peoples.html'
 
@@ -84,7 +79,7 @@ class PeoplesListView(BaseAbonListView):
 
 
 @method_decorator((login_required, lib.decorators.only_admins), name='dispatch')
-class GroupListView(BaseAbonListView):
+class GroupListView(BaseOrderedFilteringList):
     context_object_name = 'groups'
     template_name = 'abonapp/group_list.html'
     queryset = Group.objects.annotate(usercount=Count('abon'))
@@ -212,7 +207,7 @@ def abonamount(request, gid, uname):
 
 @method_decorator((login_required, lib.decorators.only_admins), name='dispatch')
 @method_decorator(permission_required('group_app.can_view_group', (Group, 'pk', 'gid')), name='dispatch')
-class DebtsListView(BaseAbonListView):
+class DebtsListView(BaseOrderedFilteringList):
     context_object_name = 'invoices'
     template_name = 'abonapp/invoiceForPayment.html'
 
@@ -230,7 +225,7 @@ class DebtsListView(BaseAbonListView):
 
 @method_decorator((login_required, lib.decorators.only_admins), name='dispatch')
 @method_decorator(permission_required('group_app.can_view_group', (Group, 'pk', 'gid')), name='dispatch')
-class PayHistoryListView(BaseAbonListView):
+class PayHistoryListView(BaseOrderedFilteringList):
     context_object_name = 'pay_history'
     template_name = 'abonapp/payHistory.html'
 
@@ -756,7 +751,7 @@ def abon_ping(request):
 
 
 @method_decorator((login_required, lib.decorators.only_admins,), name='dispatch')
-class DialsListView(BaseAbonListView):
+class DialsListView(BaseOrderedFilteringList):
     context_object_name = 'logs'
     template_name = 'abonapp/dial_log.html'
 
diff --git a/agent/commands/dhcp.py b/agent/commands/dhcp.py
index 92051a8..92fc7b5 100644
--- a/agent/commands/dhcp.py
+++ b/agent/commands/dhcp.py
@@ -9,7 +9,7 @@ def dhcp_commit(client_ip: str, client_mac: str, switch_mac: str, switch_port: i
         dev = Device.objects.get(mac_addr=switch_mac)
         mngr_class = dev.get_manager_klass()
 
-        if mngr_class.is_use_device_port():
+        if mngr_class.get_is_use_device_port():
             abon = Abon.objects.get(dev_port__device=dev,
                                     dev_port__num=switch_port,
                                     device=dev)
diff --git a/devapp/base_intr.py b/devapp/base_intr.py
index 3b63998..0345527 100644
--- a/devapp/base_intr.py
+++ b/devapp/base_intr.py
@@ -5,15 +5,13 @@ from easysnmp import Session
 
 from django.utils.translation import gettext
 
-from djing.lib.decorators import abstract_static_method
-
 ListOrError = Union[
     Iterable,
     Union[Exception, Iterable]
 ]
 
 
-class DeviceImplementationError(Exception):
+class DeviceImplementationError(NotImplementedError):
     pass
 
 
@@ -25,10 +23,15 @@ class DevBase(object, metaclass=ABCMeta):
     def __init__(self, dev_instance=None):
         self.db_instance = dev_instance
 
-    @abstract_static_method
-    def description() -> AnyStr:
+    @property
+    @abstractmethod
+    def description(self) -> AnyStr:
         pass
 
+    @classmethod
+    def get_description(cls):
+        return cls.description
+
     @abstractmethod
     def reboot(self):
         pass
@@ -49,23 +52,29 @@ class DevBase(object, metaclass=ABCMeta):
     def get_template_name(self) -> AnyStr:
         """Return path to html template for device"""
 
+    @property
     @abstractmethod
     def has_attachable_to_subscriber(self) -> bool:
         """Can connect device to subscriber"""
 
-    @abstract_static_method
-    def is_use_device_port() -> bool:
+    @property
+    @abstractmethod
+    def is_use_device_port(self) -> bool:
         """True if used device port while opt82 authorization"""
 
-    # fixme: only that is abstract static
-    @abstract_static_method
-    def validate_extra_snmp_info(v: str) -> None:
+    @classmethod
+    def get_is_use_device_port(cls) -> bool:
+        return cls.is_use_device_port
+
+    @classmethod
+    def validate_extra_snmp_info(cls, v: str) -> None:
         """
         Validate extra snmp field for each device.
         If validation failed then raise en exception from djing.lib.tln.ValidationError
         with description of error.
         :param v: String value for validate
         """
+        raise NotImplementedError
 
     @abstractmethod
     def register_device(self, extra_data: Dict):
diff --git a/devapp/dev_types.py b/devapp/dev_types.py
index 7baf5e0..ee07a11 100644
--- a/devapp/dev_types.py
+++ b/devapp/dev_types.py
@@ -60,14 +60,14 @@ class DLinkPort(BasePort):
 
 
 class DLinkDevice(DevBase, SNMPBaseWorker):
+    has_attachable_to_subscriber = True
+    description = _('DLink switch')
+    is_use_device_port = True
+
     def __init__(self, dev_instance):
         DevBase.__init__(self, dev_instance)
         SNMPBaseWorker.__init__(self, dev_instance.ip_address, dev_instance.man_passw, 2)
 
-    @staticmethod
-    def description():
-        return _('DLink switch')
-
     def reboot(self):
         return self.get_item('.1.3.6.1.4.1.2021.8.1.101.1')
 
@@ -103,15 +103,8 @@ class DLinkDevice(DevBase, SNMPBaseWorker):
     def get_template_name(self):
         return 'ports.html'
 
-    def has_attachable_to_subscriber(self) -> bool:
-        return True
-
-    @staticmethod
-    def is_use_device_port():
-        return True
-
-    @staticmethod
-    def validate_extra_snmp_info(v: str) -> None:
+    @classmethod
+    def validate_extra_snmp_info(cls, v: str) -> None:
         # Dlink has no require snmp info
         pass
 
@@ -142,14 +135,14 @@ class ONUdev(BasePort):
 
 
 class OLTDevice(DevBase, SNMPBaseWorker):
+    has_attachable_to_subscriber = False
+    description = _('PON OLT')
+    is_use_device_port = False
+
     def __init__(self, dev_instance):
         DevBase.__init__(self, dev_instance)
         SNMPBaseWorker.__init__(self, dev_instance.ip_address, dev_instance.man_passw, 2)
 
-    @staticmethod
-    def description():
-        return gettext('PON OLT')
-
     def reboot(self):
         pass
 
@@ -187,15 +180,8 @@ class OLTDevice(DevBase, SNMPBaseWorker):
     def get_template_name(self):
         return 'olt.html'
 
-    def has_attachable_to_subscriber(self) -> bool:
-        return False
-
-    @staticmethod
-    def is_use_device_port():
-        return False
-
-    @staticmethod
-    def validate_extra_snmp_info(v: str) -> None:
+    @classmethod
+    def validate_extra_snmp_info(cls, v: str) -> None:
         # Olt has no require snmp info
         pass
 
@@ -208,6 +194,10 @@ class OLTDevice(DevBase, SNMPBaseWorker):
 
 
 class OnuDevice(DevBase, SNMPBaseWorker):
+    has_attachable_to_subscriber = True
+    description = _('PON ONU')
+    is_use_device_port = False
+
     def __init__(self, dev_instance):
         DevBase.__init__(self, dev_instance)
         dev_ip_addr = None
@@ -223,15 +213,11 @@ class OnuDevice(DevBase, SNMPBaseWorker):
             ))
         SNMPBaseWorker.__init__(self, dev_ip_addr, dev_instance.man_passw, 2)
 
-    @staticmethod
-    def description() -> AnyStr:
-        return gettext('PON ONU')
-
     def reboot(self):
         pass
 
     def get_ports(self) -> ListOrError:
-        return []
+        return ()
 
     def get_device_name(self):
         pass
@@ -242,13 +228,6 @@ class OnuDevice(DevBase, SNMPBaseWorker):
     def get_template_name(self):
         return "onu.html"
 
-    def has_attachable_to_subscriber(self) -> bool:
-        return True
-
-    @staticmethod
-    def is_use_device_port():
-        return False
-
     def get_details(self):
         if self.db_instance is None:
             return
@@ -274,7 +253,7 @@ class OnuDevice(DevBase, SNMPBaseWorker):
             return {'err': "%s: %s" % (_('ONU not connected'), e)}
 
     @staticmethod
-    def validate_extra_snmp_info(v: str) -> None:
+    def validate_extra_snmp_info(cls, v: str) -> None:
         # DBCOM Onu have en integer snmp port
         try:
             int(v)
@@ -330,9 +309,8 @@ class EltexPort(BasePort):
 
 
 class EltexSwitch(DLinkDevice):
-    @staticmethod
-    def description():
-        return _('Eltex switch')
+    description = _('Eltex switch')
+    is_use_device_port = False
 
     def get_ports(self) -> ListOrError:
         res = []
@@ -355,13 +333,6 @@ class EltexSwitch(DLinkDevice):
         tm = RuTimedelta(timedelta(seconds=uptimestamp / 100)) or RuTimedelta(timedelta())
         return tm
 
-    def has_attachable_to_subscriber(self) -> bool:
-        return True
-
-    @staticmethod
-    def is_use_device_port():
-        return False
-
     def monitoring_template(self, *args, **kwargs) -> Optional[str]:
         device = self.db_instance
         return plain_ip_device_mon_template(device)
@@ -378,9 +349,7 @@ def conv_signal(lvl: int) -> float:
 
 
 class Olt_ZTE_C320(OLTDevice):
-    @staticmethod
-    def description():
-        return gettext('OLT ZTE C320')
+    description = _('OLT ZTE C320')
 
     def get_fibers(self):
         fibers = ({
@@ -443,9 +412,7 @@ class Olt_ZTE_C320(OLTDevice):
 
 
 class ZteOnuDevice(OnuDevice):
-    @staticmethod
-    def description():
-        return _('ZTE PON ONU')
+    description = _('ZTE PON ONU')
 
     def get_details(self) -> Optional[Dict]:
         if self.db_instance is None:
@@ -472,8 +439,8 @@ class ZteOnuDevice(OnuDevice):
     def get_template_name(self):
         return 'onu_for_zte.html'
 
-    @staticmethod
-    def validate_extra_snmp_info(v: str) -> None:
+    @classmethod
+    def validate_extra_snmp_info(cls, v: str) -> None:
         # for example 268501760.5
         try:
             fiber_num, onu_port = v.split('.')
diff --git a/devapp/models.py b/devapp/models.py
index 2b6575f..7933583 100644
--- a/devapp/models.py
+++ b/devapp/models.py
@@ -90,8 +90,8 @@ class Device(models.Model):
 
     # Can attach device to subscriber in subscriber page
     def has_attachable_to_subscriber(self) -> bool:
-        mngr = self.get_manager_object()
-        return mngr.has_attachable_to_subscriber()
+        mngr = self.get_manager_klass()
+        return mngr.has_attachable_to_subscriber
 
     def __str__(self):
         return "%s: (%s) %s %s" % (self.comment, self.get_devtype_display(), self.ip_address or '', self.mac_addr or '')
diff --git a/devapp/views.py b/devapp/views.py
index 73a5c87..f1adfec 100644
--- a/devapp/views.py
+++ b/devapp/views.py
@@ -650,7 +650,7 @@ class OnDeviceMonitoringEvent(global_base_views.SecureApiView):
             recipients = UserProfile.objects.get_profiles_by_group(device_down.group.pk)
             names = list()
 
-            for recipient in recipients:
+            for recipient in recipients.iterator():
                 send_notify(
                     msg_text=gettext(notify_text) % {
                         'device_name': "%s(%s) %s" % (
diff --git a/djing/lib/__init__.py b/djing/lib/__init__.py
index 0442c0a..199547e 100644
--- a/djing/lib/__init__.py
+++ b/djing/lib/__init__.py
@@ -38,24 +38,16 @@ def safe_int(i):
 # классы передавать для того чтоб по значению кода из базы понять какой класс нужно взять для нужной функциональности.
 # Например по коду в базе вам нужно определять как считать тариф абонента, что реализовано в возвращаемом классе.
 class MyChoicesAdapter(Iterator):
-    chs = tuple()
-    current_index = 0
-    _max_index = 0
+    _chs = None
 
     # На вход принимает кортеж кортежей, вложенный из 2х элементов: кода и класса, как: TARIFF_CHOICES
     def __init__(self, choices):
-        self._max_index = len(choices)
-        self.chs = choices
+        self._chs = iter(choices)
 
     def __next__(self):
-        if self.current_index >= self._max_index:
-            raise StopIteration
-        else:
-            e = self.chs
-            ci = self.current_index
-            res = e[ci][0], e[ci][1].description()
-            self.current_index += 1
-            return res
+        obj = next(self._chs)
+        choice_code, choice_class = obj
+        return choice_code, choice_class.get_description()
 
 
 # Russian localized timedelta
diff --git a/djing/lib/decorators.py b/djing/lib/decorators.py
index 2c0d49d..2a69fed 100644
--- a/djing/lib/decorators.py
+++ b/djing/lib/decorators.py
@@ -55,13 +55,3 @@ def hash_auth_view(fn):
         else:
             return HttpResponseForbidden('Access Denied')
     return wrapped
-
-
-class abstract_static_method(staticmethod):
-    __slots__ = ()
-
-    def __init__(self, func):
-        super(abstract_static_method, self).__init__(func)
-        func.__isabstractmethod__ = True
-
-    __isabstractmethod__ = True
diff --git a/docs/dev.md b/docs/dev.md
index b9f728e..09ca0ec 100644
--- a/docs/dev.md
+++ b/docs/dev.md
@@ -47,10 +47,9 @@ class EltexPort(BasePort):
 Теперь реализация для свича:
 ```python
 class EltexSwitch(DLinkDevice):
-
-    @staticmethod
-    def description():
-        return _('Eltex switch')
+    has_attachable_to_subscriber = False
+    description = _('Eltex switch')
+    is_use_device_port = False
 
     def get_ports(self):
         #nams = self.get_list('.1.3.6.1.4.1.171.10.134.2.1.1.100.2.1.3')
@@ -77,14 +76,8 @@ class EltexSwitch(DLinkDevice):
         tm = RuTimedelta(timedelta(seconds=uptimestamp/100)) or RuTimedelta(timedelta())
         return tm
 
-    def has_attachable_to_subscriber(self) -> bool:
-        return False
-
-    @staticmethod
-    def is_use_device_port():
-        return False
 ```
-Метод **@description** Просто отображает человекопонятное название вашего устройства в биллинге.
+Свойство **@description** Просто отображает человекопонятное название вашего устройства в биллинге.
 Заметьте что строка на английском и заключена в процедуру **_** (это ugettext_lazy, см. в импорте вверху файла),
 это локализация для текущего языка. Про локализацию можно почитать в соответствующем разделе [django translation](https://docs.djangoproject.com/en/1.11/topics/i18n/translation/).
 
@@ -98,11 +91,11 @@ class EltexSwitch(DLinkDevice):
 Метод **@uptime**, понятно что возвращает, укажите нужный OID. Вернётся тип *RuTimedelta*, это переопределённый тип **timedelta**, я его реализовал
 для локализации временного промежутка на русский.
 
-Метод **@has_attachable_to_subscriber** возвращает правду если это устройство можно привязать к абоненту.
+Свойство **@has_attachable_to_subscriber** возвращает правду если это устройство можно привязать к абоненту.
 Например у Dlink стоит True потому что Dlink стоит во многих местах на доступе, и его порты принадлежат
 абонентам при авторизации.
 
-Статический метод **@is_use_device_port** используется в DHCP чтоб понять что мы используем для привязки к абоненту всё устройство или
+Свойство **@is_use_device_port** используется в DHCP чтоб понять что мы используем для привязки к абоненту всё устройство или
 только порт устройства. Например, если у устройства только 1 порт абонента (PON ONU), и мы привязываем этого абонента ко всему устройству
 а не к порту, то нужно вернуть False, На обычных свичах где мы авторизуем абонента на порту возвращаем True.
 
diff --git a/ip_pool/templates/ip_pool/net_add.html b/ip_pool/templates/ip_pool/net_add.html
index 3dbb6cd..6fb8450 100644
--- a/ip_pool/templates/ip_pool/net_add.html
+++ b/ip_pool/templates/ip_pool/net_add.html
@@ -11,6 +11,8 @@
     </ol>
 {% endblock %}
 
+{% block page-header %}{% trans 'Add new subnet' %}{% endblock %}
+
 {% block main %}
     <form action="{% url 'ip_pool:net_add' %}" method="post">{% csrf_token %}
     <div class="panel panel-default">
diff --git a/mapapp/urls.py b/mapapp/urls.py
index def6b23..e3673e3 100644
--- a/mapapp/urls.py
+++ b/mapapp/urls.py
@@ -7,8 +7,8 @@ app_name = 'mapapp'
 urlpatterns = [
     url(r'^$', views.home, name='home'),
     url(r'^options$', views.OptionsListView.as_view(), name='options'),
-    url(r'^options/add$', views.dot, name='add_dot'),
-    url(r'^options/(?P<did>\d+)/edit$', views.dot, name='edit_dot'),
+    url(r'^options/add$', views.dot_edit, name='add_dot'),
+    url(r'^options/(?P<did>\d+)/edit$', views.dot_edit, name='edit_dot'),
     url(r'^options/(?P<did>\d+)/remove$', views.remove, name='remove_dot'),
     url(r'^options/(?P<did>\d+)/add_dev$', views.add_dev, name='add_dev'),
     url(r'^preload_devices$', views.preload_devices, name='preload_devices'),
diff --git a/mapapp/views.py b/mapapp/views.py
index 1b61c28..3989678 100644
--- a/mapapp/views.py
+++ b/mapapp/views.py
@@ -31,8 +31,8 @@ def home(request):
     dots = Dot.objects.all()
     groups = Group.objects.all()
     return render(request, 'maps/ya_index.html', {
-        'dots': dots,
-        'groups': groups
+        'dots': dots.iterator(),
+        'groups': groups.iterator()
     })
 
 
@@ -49,7 +49,7 @@ class OptionsListView(BaseListView):
 
 
 @login_required
-def dot(request, did=0):
+def dot_edit(request, did=0):
     if not request.user.is_superuser:
         return redirect('/')
     try:
@@ -101,9 +101,9 @@ def remove(request, did):
 def get_dots(request):
     if not request.user.is_superuser:
         return HttpResponseForbidden('you have not super user')
-    dots = Dot.objects.prefetch_related('devices').annotate(devcount=Count('devices')).defer('attachment')
+    dots = Dot.objects.prefetch_related('devices').annotate(devcount=Count('devices')).defer('attachment').iterator()
 
-    def fill_dev(dev):
+    def fill_dev(dev: Device):
         return {
             'status': dev.status,
             'comment': dev.comment
@@ -169,15 +169,15 @@ def modal_add_dot(request):
 def preload_devices(request):
     if not request.user.is_superuser:
         return HttpResponseForbidden('you have not super user')
-    grp = request.GET.get('grp')
-    dot = request.GET.get('dot')
-    all_devices = Device.objects.filter(group__id=grp)
-    dot_devices = Device.objects.filter(dot__id=dot)
-
-    dot_devices_ids = [dev.pk for dev in dot_devices]
+    grp_id = request.GET.get('grp')
+    dot_id = request.GET.get('dot')
+    all_devices = Device.objects.filter(group__id=grp_id)
+    dot_devices = Device.objects.filter(dot__id=dot_id)
+    dot_devices_ids = tuple(dev.pk for dev in dot_devices.iterator())
+    del dot_devices
 
     ret = render_to_text('maps/preload_devices_tmpl.html', {
-        'all_devices': all_devices,
+        'all_devices': all_devices.iterator(),
         'dot_devices_ids': dot_devices_ids
     })
     return HttpResponse(ret, content_type='text/html')
@@ -195,7 +195,7 @@ def dot_tooltip(request):
     except Dot.DoesNotExist:
         pass
     return render_to_text('maps/map_tooltip.html', {
-        'devs': devs,
+        'devs': devs.iterator(),
         'dot': dot
     })
 
@@ -213,8 +213,8 @@ def add_dev(request, did):
         selected_user_group = safe_int(request.POST.get('selected_user_group'))
 
         existing_devs = Device.objects.filter(group__id=selected_user_group or param_user_group)
-        if existing_devs.count() > 0:
-            dot.devices.remove(*[dev.pk for dev in existing_devs])
+        if existing_devs.exists():
+            dot.devices.remove(*(dev.pk for dev in existing_devs.iterator()))
         dot.devices.add(*selected_devs)
 
         url = resolve_url('mapapp:add_dev', did=dot.pk)
@@ -222,9 +222,9 @@ def add_dev(request, did):
     else:
         existing_devs = Device.objects.filter(group=param_user_group)
     return render(request, 'maps/add_device.html', {
-        'groups': groups,
+        'groups': groups.iterator(),
         'dot': dot,
-        'existing_devs': existing_devs,
+        'existing_devs': existing_devs.iterator(),
         'grp': param_user_group,
         'dot_devices_ids': [dev.pk for dev in Device.objects.filter(dot=dot)]
     })
diff --git a/tariff_app/base_intr.py b/tariff_app/base_intr.py
index 970dbe9..db903ff 100644
--- a/tariff_app/base_intr.py
+++ b/tariff_app/base_intr.py
@@ -14,13 +14,17 @@ class TariffBase(metaclass=ABCMeta):
         """Calculate deadline date"""
         raise NotImplementedError
 
-    @staticmethod
-    def description() -> AnyStr:
+    @property
+    @abstractmethod
+    def description(self) -> AnyStr:
         """
         Usage in djing.lib.MyChoicesAdapter for choices fields.
         :return: human readable description
         """
-        raise NotImplementedError
+
+    @classmethod
+    def get_description(cls):
+        return cls.description
 
     @staticmethod
     def manage_access(abon) -> bool:
@@ -51,8 +55,12 @@ class PeriodicPayCalcBase(metaclass=ABCMeta):
         """
         raise NotImplementedError
 
-    @staticmethod
-    def description() -> AnyStr:
+    @property
+    @abstractmethod
+    def description(self) -> AnyStr:
         """Return text description.
         Uses in djing.lib.MyChoicesAdapter for CHOICES fields"""
-        raise NotImplementedError
+
+    @classmethod
+    def get_description(cls):
+        return cls.description
diff --git a/tariff_app/custom_tariffs.py b/tariff_app/custom_tariffs.py
index e9efd92..454260c 100644
--- a/tariff_app/custom_tariffs.py
+++ b/tariff_app/custom_tariffs.py
@@ -1,6 +1,5 @@
 # -*- coding: utf-8 -*-
 from datetime import timedelta, datetime
-from typing import AnyStr
 
 from django.utils import timezone
 from django.utils.translation import gettext as _
@@ -11,6 +10,8 @@ from random import uniform
 
 
 class TariffDefault(TariffBase):
+    description = _('Base calculate functionality')
+
     def __init__(self, abon_tariff):
         # assert isinstance(abon_tariff, AbonTariff)
         self.abon_tariff = abon_tariff
@@ -44,25 +45,20 @@ class TariffDefault(TariffBase):
                                    hour=23, minute=59, second=59)
         return last_month_date
 
-    @staticmethod
-    def description() -> AnyStr:
-        return _('Base calculate functionality')
-
 
 class TariffDp(TariffDefault):
+    description = 'IS'
     # в IS снимается вся стоимость тарифа вне зависимости от времени использования
 
     # просто возвращаем всю стоимость тарифа
     def calc_amount(self) -> float:
         return float(self.abon_tariff.tariff.amount)
 
-    @staticmethod
-    def description() -> AnyStr:
-        return 'IS'
-
 
 # Как в IS только не на время, а на 10 лет
 class TariffCp(TariffDp):
+    description = _('Private service')
+
     def calc_deadline(self) -> datetime:
         # делаем время окончания услуги на 10 лет вперёд
         nw = timezone.now()
@@ -70,10 +66,6 @@ class TariffCp(TariffDp):
                                   hour=23, minute=59, second=59)
         return long_long_time
 
-    @staticmethod
-    def description() -> AnyStr:
-        return _('Private service')
-
 
 # Первый - всегда по умолчанию
 TARIFF_CHOICES = (
@@ -84,6 +76,8 @@ TARIFF_CHOICES = (
 
 
 class PeriodicPayCalcDefault(PeriodicPayCalcBase):
+    description = _('Default periodic pay')
+
     def calc_amount(self, model_object) -> float:
         return model_object.amount
 
@@ -91,12 +85,10 @@ class PeriodicPayCalcDefault(PeriodicPayCalcBase):
         # TODO: решить какой будет расёт периодических платежей
         return datetime.now() + timedelta(days=30)
 
-    @staticmethod
-    def description() -> AnyStr:
-        return _('Default periodic pay')
-
 
 class PeriodicPayCalcCustom(PeriodicPayCalcDefault):
+    description = _('Custom periodic pay')
+
     def calc_amount(self, model_object) -> float:
         """
         :param model_object: it is a instance of models.PeriodicPay model
@@ -104,10 +96,6 @@ class PeriodicPayCalcCustom(PeriodicPayCalcDefault):
         """
         return uniform(1, 10)
 
-    @staticmethod
-    def description() -> AnyStr:
-        return _('Custom periodic pay')
-
 
 PERIODIC_PAY_CHOICES = (
     ('df', PeriodicPayCalcDefault),