The Nu-Set 2040 LockBox is a four number combination locking shackle that comes with a protective vinyl jacket on the outside. The vinyl jacket prevents the lock from scratching doors and other surfaces as well as prevents water damage on the lock itself. The NuSet 2040 is easy to set up and easy to use. Its unique combination locking shackle on top even allows the owner of the lock box to open the shackle without a key.  Show less