Permanent locking point for indoor or outdoor use to keep vehicles and bicycles safe. Attach to ground, wall, truck or trailer bed (accessory kit needed for truck or trailer bed). 16mm hardened carbon alloy steel shackle. Includes 2 masonry bits (1 initial Pilot hole, 1 final moly-bolt diameter). steel shackle lays flat within domed body When not in use making it safe to walk or drive over. Recommended for both residential and commercial applications.