diff --git a/src/pyfroniusreg/froniusreg.py b/src/pyfroniusreg/froniusreg.py
index e9039a4..4e605a4 100644
--- a/src/pyfroniusreg/froniusreg.py
+++ b/src/pyfroniusreg/froniusreg.py
@@ -3,12 +3,16 @@
 # Copyright 2024, Paul Warren <pwarren@pwarren.id.au>
 # Licensed under AGPLv3, See LICENSE.md for terms
 
+from typing import Any
+
 from pymodbus.constants import Endian
 from pymodbus.payload import BinaryPayloadDecoder, BinaryPayloadBuilder
-
+from pymodbus.client.base import ModbusBaseClient 
 
 class DataType:
     def __init__(self, width, decode, add):
+        width: int
+        
         self._width = width
         self._decode = decode
         self._add = add
@@ -30,28 +34,28 @@ class DataType:
 
 
 # helper functions for DataType constructors
-def decode_string8(decoder):
+def decode_string8(decoder) -> str:
     try:
         return str(decoder.decode_string(8).decode("utf-8"))
     except UnicodeDecodeError:
         return decoder.decode_string(8)
 
 
-def decode_string16(decoder):
+def decode_string16(decoder) -> str:
     try:
         return str(decoder.decode_string(16).decode("utf-8"))
     except UnicodeDecodeError:
         return decoder.decode_string(16)
 
 
-def decode_string32(decoder):
+def decode_string32(decoder) -> str:
     try:
         return str(decoder.decode_string(32).decode("utf-8"))
     except UnicodeDecodeError:
         return decoder.decode_string(32)
 
 
-def encode_16bit_int(encoder, value):
+def encode_16bit_int(encoder, value) -> int:
     return encoder.add_16bit_int(int(value))
 
 
@@ -124,16 +128,18 @@ class FroniusReg:
 
 
 class ScaledFroniusReg:
-    def __init__(self, value_register, scale_register):
+    def __init__(self, value_register: FroniusReg, scale_register: FroniusReg):
+        "A nicer way of dealing with scaled registers"
         self.value_register = value_register
         self.scale_register = scale_register
 
-    def get(self, modbus_client):
+    def get(self, modbus_client: ModbusBaseClient) -> float:
+        "Return the value_register's value, scaled by scale_register."
         return self.value_register.get(modbus_client) * 10 ** self.scale_register.get(
             modbus_client
         )
 
-    def set(self, modbus_client, value):
+    def set(self, modbus_client: ModbusBaseClient, value: [ int, float, str ]):
         return self.value_register.set(
-            modbus_client, value / 10 ** self.scale_register.get(modbus_client)
+            modbus_client, value / 10 ** self.scale_register.get(modbus_client),
         )