This is the Hanger 9 Digital Servo and Receiver Current Meter. Hangar 9’s Digital Servo and Receiver Current Meter lets modelers check current flow between multiple linkages. It will monitor overall voltage between the battery and receiver, charge current between the charger and charge jack, or current draw when used between the receiver and servo. Modelers can even monitor discharge current between the charge jack and battery cycler. All voltage information is displayed on the easy-to-read digital display and can be switched between volts or amps. The unit comes wired with universal connectors allowing it to be used with all popular systems.