Qingdao Tongshuai Door Manufecturer is the proffessional manufecturer of all kinds of Industrial doors Descpription of the Doors 1. Material: best stainless steel, which can effectively prevent the extension door from rust and corrosion. 2. Surface: fine smooth surface, beautiful appearance, waterproof, dust-resistance, 3. Extension structure: with double-plane link lever, 4. Wheel: stainless steel link lever slide guide, steady moving, abrasion proof, dust-resistance, and long using time . 5. Long distance between two guide rails, low barycenter, fine stabilization,strong outside & wind force resistance. 6. No noise, flexibility. 7. Optional: LED display screen. The device for defending to climb and bump 8. TS extension door is the first remote controlling extension door which has win three national patents. Please browse our website http://www.commanderdoor.com for more information,or email me directly sales@tongshuaidoor.com.Thanks