... rising up when being blocked2. Torsion spring Breakage Prevention Device: activating when torsion spring breaking3. Anti-Dropping Track: guide ... : Remote control, wall switch or manual4. Industrial torsion spring Life: more than 3,000 times’ lifting5. EPDM ... lift and half standard lift5Safety systemsCable safety system, Spring safety system, Airbag bottom seals6HardwaresZinc plated steel hardwares. ...