Variable Frequency Speed?? Controller for Spindle Motor Speed Control Features: The inverters is equipped with a large radiators, which has good heat dissipation effect. By optimizing PWMcontrol technology and electromagnetic compatibility, it meets the user’s needs for low noise and low electromagnetic The variable speed adopts a unique control methods to realize the high torques, high precisions, wide speed control ranges with excellent performances. It has good anti-jump performances and the ability to adapt to rough power supply, temperature, humidity and exposure to dust, which greatly improves stability. The and wiring are simple, and wires are with screw terminals, which is more convenient. Specifications: Power: 750W/1500W/2200W Size: As shown in the picture Package Includes: 1x Variable Frequency note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item.