... ,CE certificate JCD series high-grade type heavy hammer exhaust fan features.1. Certificate, CE.2. Frame, all the frames are ... , thickness 1.2mm, mirror face.4. Impeller, casting aluminum alloy impeller , diameter 300mm. 5. Bearing of impeller, permanently sealed bearing, size 633313.6 ... , 2 year , the whole machine. swung drop hammer shutter exhaust fan