This product is anemergency release lock. It is made of solid materials. It is safe and durable. It can serve you for a long time without being easily damaged. It is an excellent emergency release lock that can bring you more convenience, allowing you to have a more comfortable experience.FeaturesColor:As ShownMaterial:Steel wire, metalSize:5.50X5.50X4.00cm2.16X2.16X1.57in This door lock allows manual opening of the garage door in the event of a power failure or other opener failure. This garage door emergency release lock is universally compatible with most brands of garage door openers. Made of diecast construction, brushed steel wire and metal for durability. Widely used in bank, hotel, store, school, home, mall, and etc. Simple installation, easy to use for beginner or professional, allow you to use in an orderly and stable way.Packing list1 x quick release lock2 x keys