Details about Maer axial fan 400mm model:YSWF74M4-470N-400/YDWF74M4-470N-400 voltage: 380V / 220V frenquency:50Hz air volume: 4,235m3/h/4,235m3/h speed: 1,400RPM/1,400RPM input power: 190W/195W current: 0.48A/0.88A noise:69dBA/69dBA impeller:5 impellers net: 6kg insulater class: B (F is possible) ------------------------------------------------------------------------------ model:YSWF74M6-470N-400/YDWF74M6-470N-400 voltage: 380V / 220V frenquency:50Hz air volume: 3,290m3/h/3,290m3/h speed: 920RPM/920RPM input power: 120W/120W current: 0.38A/0.56A noise:60dBA/60dBA impeller:5 impellers net: 6kg insulater class: B (F is possible) ------------------------------------------------------------------------------