JMT G.t.power Digital LED Servo Tester for Rc Car Trucks Planes Helicopters G.T.Power Digital LED Servo Tester for RC Car Trucks Planes Helicopters This is a professional servo tester which is durable, easy to operatie, fully functional,small in volume and light in weight The Servo tester uses intelligent MCU control to make it works very stable, and it's a necessary tool for RC users.