Descending life line

Summary

A descending life line (DLL), also known by wanganggi (Korean: 완강기), kankōki (Japanese: 緩降機), or huǎnjiàngqì, is a type of emergency descent device installed in mid-rise buildings across East Asia, intended for use when conventional evacuation routes are blocked. Like auto belays used in rock climbing, it slowly lowers the user to the ground with their own weight. Some types are single-use only while others can be used multiple times. DLLs are usually installed near windows or balconies.