I added this to avoid providing keys to a maid service. I provided them with their own code which took seconds to program. When that service didn't work out, it took me seconds again to wipe out their code by exchanging it for another one. I was very glad to have purchased this excellent lock rather than worrying if they had made a copy of my physical key or having to change locks. I also liked the convenience of changing that lock rather than having to arrange time away from work during the day to pick up my key. Convenience all around. The lock is very easy to use and as secure as a keyed deadbolt.