This is a set of cylinder lock and keys. A cylinder lock can be locked and unlocked by inserting and turning the key. It includes the cylinder body with the keyhole, the keys, and mounting hardware and screws. "Cylinder" in English means "a tube," and it's called this because the main body where the key is inserted is cylindrical. It is used for security purposes in various places such as residential doors, lockers, and drawers. Thank you for viewing. I am selling this because my mother is closing her shop. Thank you for your purchase. Thank you for viewing.