I've got this type of lock on all my exterior doors. I absolutely love them. It is simple to program with a 4, 5, or 6 digit number. I can give the code of the day to my housekeeper and never have to worry about a key getting into the wrong hands. We are never locked out of the house. I even use one of the locks on my detached garage. I can put things out there I don't want my kids to see or get into (ie Christmas presents).