1. The speed is stable and does not beat with the voltage fluctuations of the power grid. 2. Wide voltage, wide frequency AC transmission 115 to 230VAC/50 to 60Hz. 3. Intelligently protect the fan and stop working after detecting foreign objects stuck in the fan leaves. 4. High power factor, good speed control performance, simple control, can be no extreme speed control. 5. High energy saving, high efficiency, long life, low vibration, low noise and continuous and uninterrupted operation. 6. Constant air volume output, detection of air port foreign objects blocked to increase speed, increase air volume (non-full speed state).