1Stretch out to open the door when in use, and let it go when not in use, it will automatically spring back to the waist to avoid frequent key loss caused by random throwing away. 2The key ring can be hung on a belt or backpack, more convenient to carry to the outside. 3Do not pull the wire with excessive force, which may easily cause problems with the return spring. 4Built-in spring, easy to expand and contract, compact with carabiner, provide better use feeling. 5Made of high quality stainless steel material, firm and durable, provide longer service life.