1. Changing frequency changing rotation speed,  low fall of rotation speed and high output torque;

2.Rotation speed, count, temperature, air pressure and advance angle are displayed in digits mode;

3. Seven kinds of rotation speeds presetting;

4. Built-in air resource;

5. Constant temperature controlled;

6. The functions of over voltage, overload and short circuit protection;

7. Operating position: arbitrary side of the two work sides of the test stand;

8. High measurement precision, ultra low noise.