Our exhaust fan with external rotor are able to work with condensing and evaporating units with 4 to 16 fins per inch on the heat exchanger. Protection class: IP54CL.B or CL.FLife at 25C: 50000hoursBlade dia: 200,250,300,350,400,450,500,550,600,650,710,Sucking and blowingDirection of Rotation:CW or CCWOperating temperature from : -30 60CBlades angle can be set to 35 degreesBearing system: Ball bearing Our 450 serial blueexhaust fan with external rotor specification: Item NO.Voltage(V)HZ.CURR.(A)POWER(W)SPEED(R/min)Capacitor(µF)NET WEIGHT(KG)NOISE(dBA)Max airflow(m/h)YWF4S-450220501.20250135087.5684620YWF4T-450380500.642501380/7.5684800YWF6S-450220500.7215092067.5603800YWF6T-450380500.40150920/7.5603520