This is a professional servo tester which is , easy to operatie, fully functional, small in volume and light in weight. The Servo tester uses intelligent MCU control to works very stable, and it's a necessary tool for RC users. High performance-to-price ratio, combined with proprietary test algorithm, which that the test is fast and stable. For G. tester can be powered by lipo battery through the balance charging wire adaptor or DC power supply. It is both convenient and flexible. The rolling menu makes the operation clear and easy. The function setting is easy and practical which covers most parameters that end users need.The device is equipped with servo and receiver wires, which makes the measurement operation a lot easier. The device is equipped with clear and high contrast LCD Monitor to show individual parameter and menu selection. Which assures the user see the testing information accurately and completely.Bigger buttons are used over the smaller , which proves good feedback and reduces misoperations Display: LCD Input voltage:7.4 - 12V LN Mode: This function is used to test the linearity andvibration of servo. (This can also be used to test the linearity andvibration point of ESC) ED Mode: The function is used to test the endurance of servo. Mode: This function is used to test the servo's ability to neutral itself. (If equipped on the plane, you can find out the theoretic mid-point of servo exactly) DB Mode: The function is used to test the dead band of servo. (It can also be used to calculate the resolution of servo) The test can also be used to choose the servo based on differential timing. (This great for models like CCPM which need 3 servos for it's rotor head) SP Mode: This function is used to perform speed test for servo, and it allo you to choose the most competent servo based on all the parameters that is performed in the test (E.g. Reaction Time and Differential Timing) Mode: The function is used to test the ageing and life of the servo. There are some certain reparative functions for some servos. PW Mode: This function is used to test the output pulse of connector and test whether there is any problem on the signal unstable of the quiver of servo. Color:Black Material:plastic Package Contents: 1 * Professional 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.