Fangrui Product Details There Are 3 Modes To Check Servos Or Esc: Manual Mode: Turn The Knob With Different Speed, Check The Reaction Time; Neutral Mode: Make The Servo Go Back To The Neutral Point; Automatic Window Wiper Mode: Make The Servo Swing Like A Window Wipers In The Biggest Angle. It Can Connect 1-3 Servos Simultaneously And Test Such As 1-3 Servos Consistency And So On. You Can Also Connect 1-3 Esc To Test And Compare Their Reaction Time Respectively. It Can Connect 3 Servos Of The Ccpm Helicopters And Select Servos. It Can Also Connect The Servo Of Airplanes Install The Steering-box And Adjust Planes By Using Such As The Neutral Mode And So On. Ccpm Servo Consistency Master/servo Tester. The Device Also Can Be Used As A Signal Generator For Electric Speed Controller (esc). With It, You Can Test Your Motor System Without Using A Mitter And Receiver Package Contents: 1x Tester Only The Above Package Content, Other Products Are Not Included. Note: Light Shooting And Different Displays May Cause The Color Of The Ite