P03552 Sun-U Aluminum Alloy rolling door: the hidden designed operator with spring assisted mechanism offers precise balance makes opening and closing your door effortless but high speed. In addition to has a nylon felt running strip for smooth operation with minimal noise and friction.   Curtains are assembled from extruded aluminum interlocking slats, which are individually replaceable if damaged. This feature along with the additional strength from a slat type door makes them superior to continuous sheet type doors. It's 1.2mm thickness that can be single or double layer to make your door more durable. The Aluminum Alloy slat is powder coated in wide range of colors that suits any style of your building.   Specification: 1.         Quick and Quiet DC motor with a design of tiny seam, non-metallic materials for fast and slient functions. 2.         Beautiful and Durable Professional anti-rust technology, which makes the roller door beautiful, durable and anti-add and base. 3.         Automatic Safaty System Safety and anti-pressure. The door bounces upward immediately when encountering resistance in lowering; and stop immediately when encountering resistance in rising. 4.         No Worry about Power Outages Able to switch to manual mode and open the door easily when encountering power failure. 5.         Simple Fine-Tuning Patent quick locating system. Easy maintenance, no use of maintenance tools. 6.         Easy Maintenance Spring torque regulator can fine-tune the spring torque when the spring is loose because of long time using. 7.         Additional Functions Can be used for the central control system with sensor eye, UPS, smoke sensor, alarms, and other equipments to form a perfect security environment.