... or SEW.3.Door construction --Doorframe use cold-roll steel sheets of Shanghai Baosteel,2mm thickness,paint under ... -free,colour optional. --Curtain material adopt high-density industrial fabric coating, 0.8mm thickness, yellow, blue, red, white ... or car touch the falling door,it bound up automatically. Secondly,at the bottom of our door ... door aslo install emergency stop equipment fast roll up pvc door