1.Test : can be synchronized output control 4 servos. 2.Accurate Test: used to compare the performance steering gear control of the steering servo output signal can be accurate to 2us(1 milliseconds = 1000 microseconds), you can test the steering gear is to respond to changes. 3. Signal: with signal test function in the display, the input signal changes while the input the signalsynchronization output to the servo Energized automatically enter manual mode (Manual) 20us 50H analog servo signal ,frequency 50Hz. 4.Adjustable: potentiometers to decrease or increase the width of the output pulse. 5.3 Modes:S-1 manual mode (Manual)/S-2-bit mode (Neutral)/S-3 automatic mode (Automatic) 1.This Digital Servo Tester is with high accuracy. 2.You can test control 4 servos at the same time and change the test modes as you need. 3.With potentiometers, you can decrease or increase the width of the output pulse. Input voltage: DC 4.8~6V Output signal width: 800~2200us Button the Select (Note: the key switch function, circulation patterns) 1. S-1 manual mode (Manual) 2. S-2-bit mode (Neutral) 3. S-3 automatic mode (Automatic) Keys pulse width: 1. 50H analog servo signal 20us frequency 50Hz 2. 125H digital the steering gear a signal 8us frequency 125Hz 3. 250H Digital Servo signal 4us frequency 250Hz Item weight:24g Item Size: 75mmx36mmx23mm Notice: If you are a beginner, it's advisable to be assisted by an experienced adult. Colour: Black & Purple Material: ABS Item Size: 75mmx36mmx23mm Package Contents: 1 * Digital Servo Tester Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.