The Digital Multi Servo Tester ESC RC Consistency CCPM Master Speed Control offers 3 modes to check servos or ESC. The Manual Mode allows you to turn the knob to different speeds and check the reaction time. The Neutral mode makes the servo go back to the neutral point. The Automatic “Window Wiper’’ Mode makes the servo swing like a window wiper in the largest angle possible. This servo tester can connect to up to 3 servos simultaneously. You can also connect up to 3 ESCs to test and compare their reaction time respectively. It can be operated on Voltage Range 4.8V to 6V with indicator LEDs to indicate the current state in the test. It is very handy tool to have when you deal with lot of robotic projects and electronic projects in general and want to ensure the motors are working just fine.