diff --git a/ble_interface.py b/ble_interface.py
index 70a086e..05a2fa1 100644
--- a/ble_interface.py
+++ b/ble_interface.py
@@ -1,6 +1,6 @@
 from asyncio import AbstractEventLoop
 import asyncio
-from typing import Dict
+from typing import Dict, dataclass_transform
 
 from bleak import BleakClient, BleakScanner
 from bleak.backends.characteristic import BleakGATTCharacteristic
@@ -31,6 +31,7 @@ class ble_interface:
             self.CURRENT: self.__current_meas_handler,
             self.RANGE: self.__range_handler,
         }
+        self.characteristics_gain: Dict[str, Dict[int, int]] = {} # for every service, links handle with gain
 
     async def __connect(self):        
         device = await BleakScanner.find_device_by_address(self.address, cb=dict(use_bdaddr=False))
@@ -48,8 +49,28 @@ class ble_interface:
 
             self.parse_services(services)
 
+            await self.get_associated_gains(self.CURRENT)
+
             await asyncio.Event().wait()
 
+    async def get_associated_gains(self, id: str):
+        s = self.services[id]
+        for c in s.characteristics:
+            self.log.info(c.descriptors)
+            descr = c.get_descriptor(normalize_uuid_str(myUUIDs.SOURCE_GAIN_DESCR))
+            if(not descr):
+                self.log.info("descr not found")
+                continue
+
+            data = await self.client.read_gatt_descriptor(descr.handle);
+            gain = struct.unpack("<I", data)[0]
+
+            self.log.info("descr %d", gain)
+        
+            if not self.characteristics_gain:
+                self.characteristics_gain[id] = {}
+            self.characteristics_gain[id][c.handle] = gain
+    
     def parse_services(self, services: Dict[int, BleakGATTService]):
         for i in services:
             s = services[i]
@@ -95,9 +116,9 @@ class ble_interface:
     
     def __current_meas_handler(self, char: BleakGATTCharacteristic, data: bytearray):
         val = struct.unpack("<I", data)[0]
-        handle = next(i for i,c in enumerate(self.services[self.CURRENT].characteristics) if c.handle == char.handle)
+        gain = self.characteristics_gain[self.CURRENT][char.handle]
 
-        self.call_callback(self.CURRENT, handle, val)
+        self.call_callback(self.CURRENT, gain, val)
 
     def __range_handler(self, char: BleakGATTCharacteristic, data: bytearray):
         val = struct.unpack("<i", data)[0]
diff --git a/myUUIDs.py b/myUUIDs.py
index 7380ff7..a19d2c3 100644
--- a/myUUIDs.py
+++ b/myUUIDs.py
@@ -22,3 +22,6 @@ UNITLESS_UNIT_UUID = "2700"
 NSP_DESC_MAIN = "0106"
 NSP_DESC_INSIDE = "010B"
 NSP_DESC_OUTSIDE = "010C"
+
+SOURCE_GAIN_DESCR = "2920"
+