... % Wind speed: 0.35m/s, 0.45m/s Using a highly-efficient centrifugal air Introduction:Fan filter unit (FFU) is air ... ;2. Noise: less than 55dB;3. Power: 220V, 50Hz;4. Highly efficient filter (filtration efficiency is 99.99%);5. Material: armor ... steel;6. Adjustable speeds;7. Excellent performance ;8. Using a highly-efficient centrifugal air blower;9. Durable, low noise, low vibration ...