1. Impeller: multi-blade centrifugal impeller, big air pressure and air flow. 

2. Motor: high quality ball bearing motor, low power consumption and long working life.

3. Casing: made of high strength metal, spray painting smooth and good anti-corrosion property.

4. Built-in sound-absorbing material, low noise level.

5. Non-return valve: come with valve inside the outlet to prevent flow backward.