Colors:red, blue. Size:8" 12" Voltages:110v 220v Speeds:2800r/min or 3300r/m Frequencies: 50Hz or 60Hz Main material: 7pcs of shutter:made of dia-cast aluminum alloy,fan body and cover:galvanized steel,handle: die-cast plastics,cable length:3m motor: aluminum alloy,with America,Japan,Europe,Taiwan styles' plug for choosing. Application: The explosive-proof ventilator with scientific design,firm strcuture and durable,good insulative,convenient schlep points. the unit is suitable to the place where the spontaneous combustion temperature of explosive mixed-gas should be over 135°C,such as extraction and refinement of petroleum,making of various kinds of benzene,alcohol and medicine,painting,rubber producing and so on,related factroy,workshop,warehouse for ventilating