Description:This high quality small size powerful servo tester works on three different modes :Manual : turn the knob to operate the connected servo.Neutral : automatically centers the servo， very useful when assembling a new model.Automatic : makes the servo swing back and forth to both ends of the servos max throw. If “mode” button is pressed while powering up the servo tester， the throws is set to 140% instead of 100%.3 servos or 3 ESC can be connected simultaneously to the device.Package Included:1 x Servo Tester