Main Features
1)  Axial surface of oval-shaped lock has a minimum abrasion for device when connecting widely spaced metal part,like pulley,upper part of ascender,rope clamp etc.
2)   Two-step key-lock system(TL) is suitable for frequent door opening and closing,it avoids risks for forgetting to close the door in hurry and reduces risks of false door opening in operation process
3) Anti-snag system prevents it from catching clothing and fittings,reducing risks of and increasing descending speed.