diff --git a/lib/logitech_receiver/common.py b/lib/logitech_receiver/common.py
index a55f8df1..f7e59676 100644
--- a/lib/logitech_receiver/common.py
+++ b/lib/logitech_receiver/common.py
@@ -649,8 +649,7 @@ class Battery:
         elif isinstance(self.level, int):
             status = self.status.name.lower().replace("_", " ") if self.status is not None else "Unknown"
             return _("Battery: %(percent)d%% (%(status)s)") % {"percent": self.level, "status": _(status)}
-        else:
-            return ""
+        return ""
 
 
 class Alert(IntEnum):
diff --git a/lib/logitech_receiver/settings.py b/lib/logitech_receiver/settings.py
index 2acb04b9..904718f1 100644
--- a/lib/logitech_receiver/settings.py
+++ b/lib/logitech_receiver/settings.py
@@ -20,6 +20,7 @@ import struct
 import time
 
 from enum import IntEnum
+from typing import Any
 
 from solaar.i18n import _
 
@@ -276,7 +277,7 @@ class Settings(Setting):
         self._value[int(key)] = value
         self._pre_write(save)
 
-    def write_key_value(self, key, value, save=True):
+    def write_key_value(self, key, value, save=True) -> Any | None:
         assert hasattr(self, "_value")
         assert hasattr(self, "_device")
         assert key is not None
diff --git a/lib/logitech_receiver/settings_templates.py b/lib/logitech_receiver/settings_templates.py
index 7a574c36..8cc96d5b 100644
--- a/lib/logitech_receiver/settings_templates.py
+++ b/lib/logitech_receiver/settings_templates.py
@@ -33,7 +33,6 @@ from . import common
 from . import descriptors
 from . import desktop_notifications
 from . import diversion
-from . import hidpp10_constants
 from . import hidpp20
 from . import hidpp20_constants
 from . import settings
@@ -46,7 +45,6 @@ from .hidpp20_constants import ParamId
 logger = logging.getLogger(__name__)
 
 _hidpp20 = hidpp20.Hidpp20()
-_DK = hidpp10_constants.DEVICE_KIND
 _F = hidpp20_constants.SupportedFeature
 
 
@@ -1612,8 +1610,6 @@ class LEDZoneSetting(settings.Setting):
     period_field = {"name": _LEDP.period, "kind": settings.Kind.RANGE, "label": _("Period"), "min": 100, "max": 5000}
     intensity_field = {"name": _LEDP.intensity, "kind": settings.Kind.RANGE, "label": _("Intensity"), "min": 0, "max": 100}
     ramp_field = {"name": _LEDP.ramp, "kind": settings.Kind.CHOICE, "label": _("Ramp"), "choices": hidpp20.LEDRampChoices}
-    # form_field = {"name": _LEDP.form, "kind": settings.Kind.CHOICE, "label": _("Form"), "choices":
-    # _hidpp20.LEDFormChoices}
     possible_fields = [color_field, speed_field, period_field, intensity_field, ramp_field]
 
     @classmethod
@@ -1948,7 +1944,7 @@ def check_feature_settings(device, already_known) -> bool:
     return True
 
 
-def check_feature_setting(device, setting_name) -> settings.Setting | None:
+def check_feature_setting(device, setting_name: str) -> settings.Setting | None:
     for sclass in SETTINGS:
         if sclass.feature and sclass.name == setting_name and device.features:
             setting = check_feature(device, sclass)
diff --git a/lib/logitech_receiver/settings_validator.py b/lib/logitech_receiver/settings_validator.py
index b2102d04..cd241d4d 100644
--- a/lib/logitech_receiver/settings_validator.py
+++ b/lib/logitech_receiver/settings_validator.py
@@ -43,11 +43,11 @@ class Kind(IntEnum):
 
 class Validator:
     @classmethod
-    def build(cls, setting_class, device, **kwargs):
+    def build(cls, setting_class, device, **kwargs) -> Validator:
         return cls(**kwargs)
 
     @classmethod
-    def to_string(cls, value):
+    def to_string(cls, value) -> str:
         return str(value)
 
     def compare(self, args, current):
@@ -200,7 +200,7 @@ class BitFieldValidator(Validator):
             assert isinstance(byte_count, int) and byte_count >= self.byte_count
             self.byte_count = byte_count
 
-    def to_string(self, value):
+    def to_string(self, value) -> str:
         def element_to_string(key, val):
             k = next((k for k in self.options if int(key) == k), None)
             return str(k) + ":" + str(val) if k is not None else "?"
@@ -381,7 +381,7 @@ class ChoicesValidator(Validator):
         assert self._byte_count + self._read_skip_byte_count <= 14
         assert self._byte_count + len(self._write_prefix_bytes) <= 14
 
-    def to_string(self, value):
+    def to_string(self, value) -> str:
         return str(self.choices[value]) if isinstance(value, int) else str(value)
 
     def validate_read(self, reply_bytes):
@@ -465,7 +465,7 @@ class ChoicesMapValidator(ChoicesValidator):
         assert self._byte_count + self._read_skip_byte_count + self._key_byte_count <= 14
         assert self._byte_count + len(self._write_prefix_bytes) + self._key_byte_count <= 14
 
-    def to_string(self, value):
+    def to_string(self, value) -> str:
         def element_to_string(key, val):
             k, c = next(((k, c) for k, c in self.choices.items() if int(key) == k), (None, None))
             return str(k) + ":" + str(c[val]) if k is not None else "?"