This is a GORIN aluminum alloy ring lock. Mounting screws are not included, so please provide your own. I purchased this a few years ago, but I no longer use it, so I am selling it. [Brand] GORIN [Model] GR-970 RING LOCK [Material] Aluminum [Description] Includes three types of mounting bands (13, 16, 19mm) to fit various bike frames. Features a dimple key for resistance against picking and a sturdy round bar bolt within a large aluminum die-cast body ring lock. Mounting screws are not included, so please provide your own.