This multi-functional gadget has all this functions in one unit: Voltage checker Capacity checker Servo Tester PPM Signal for ESC test Battery Discharger/Balancer This 2" LCD battery checker provides you with an affordable way to monitor the condition of your batteries and allows you to easily see the total voltage, capacity, individual cell voltage, lowest & highest cell voltage, as well as the voltage difference between cells on 2S to 7S Lithium batteries with a simple tap of the buttons. You can also use the checker to monitor the total voltage of Nickel chemistry transmitter and receiver batteries from 4 to 7 cells.