... shaped by hot extrusion, which more stronger and with the function of prying resistant) . 2.Duble ... and painted in the condition of high temperature.With symmetrical coating which hard to flake away, ... corrosion, durable and nice.Using specilized exterior motor with thermel protection device, durable, low noise, easily ... Thickness:1.7mm6. Tracks:Thickness:1.7mm remote control aluminum rolling shutter