... ,CE certificate JCD series high-grade type heavy hammer exhaust fan features.1. Certificate, CE.2. Frame, all the frames are ... . Bearing of impeller, permanently sealed bearing, size 633313.6. Venture, internal diameter, 1290mm, galvanized board, thickness 1.0mm.7. Blade tip ... , 2 year , the whole machine. swung drop hammer shutter exhaust fan