... shutter doors classification: , Sliding 1.5 cold rolled steel rails (folding, bending, and high-quality spray processing), the upper ... not exceed 25CM (high shutter doors of 3m within), rails on both sides with waterproof sealing tape, waterproof widely ... and commercial home.Vehicle shutter doors:Preparation of the vertical rails using alloy materials, and the torsion spring configuration, hand, ...