... CE certificate JCD series high-grade type heavy hammer exhaust fan features.1. Certificate, CE.2. Frame, all ... galvanizing layer 200g per square meter.3. Blade, 6 pieces of blades and all the blades are made ... 5. Bearing of impeller, permanently sealed bearing, size 633313.6. Venture, internal diameter, 1290mm, galvanized board, thickness 1. ... , the whole machine. swung drop hammer shutter exhaust fan