Motor Structure: Shaded Pole motor, with impedance protection Blades: Made by injection mould with black plastic PBT+30% glass fiber + VO class of anti-flaming liquid.Frame material: Die-casting Aluminum Alloy Bearing Type: Maintain-free NMB bearing/sleeve bearingInsulation Isolation Grade: B Protection Grade: IP 54 Dielectric Withstand Voltage: AC 1800V, at 0.5mA, 50/60HzAllowable Ambient Temperature: -20 to +70 Centigrade degree (ball bearings) (Under unconcretionary) -10 to +45 Centigrade degree (sleeve bearing)Noise Lever: 25.6 - 32.5dB at normal operation Life: 30,000hours Connection way: UL1015 wire connection Packing: 40pcs/cartonUnit weight: 350g Contact with us for more details of specification .