Details about Maer axial fan 350mm model:YSWF74S4-422N-350/YDWF74S4-422N-350 voltage: 380V / 220V frenquency:50Hz air volume: 3,110m3/h/3,110m3/h speed: 1,380RPM/1,380RPM input power: 150W/150W current: 0.37A/0.7A noise:64dBA/64dBA impeller:5 impellers net: 5kg insulater class: B (F is possible) ------------------------------------------------------------------------------ model:YSWF74S6-422N-350/YDWF74S6-422N-350 voltage: 380V / 220V frenquency:50Hz air volume: 2,100m3/h/2,100m3/h speed: 915RPM/915RPM input power: 90W/90W current: 0.29A/0.45A noise:57dBA/57dBA impeller:5 impellers net: 5kg insulater class: B (F is possible)