• High-quality material: the lock is made of brass, the shackles are made of steel, and it comes with 3 brass keys. Ensures long-term use. • Manganese steel (heat treatment): designed with a hardness of up to 65 HRC, the shackles are thicker than ordinary locks, which can effectively prevent saws and scissors. • Automatic locking: no key is required to close the lock. Simply press down the shackles. • Wide application: the keyed lock is versatile and widely used on exterior doors, Hunan-style trucks, warehouses, dormitories, offices, etc.