My new home came with a different smart entry keypad, though we didn't get they physical key with it, only the code. They way it worked if someone locked it from the inside & left through a different door, you couldn't get back in through that door! Replaced it with this keypad lock and no longer have that issue. It was easy to switch out with the enclosed instructions and program our choice of key code. You can program 30 different codes, which lets you give someone a different code than you normally use, then deprogram it when it is no longer needed. I chose this lock over some of the newer more "techy" locks with cameras and mobile apps because I really don't want to worry about internet security getting in the middle of my home's security. I like that this lock is electronic & keyless, but NOT going to be prone to computer security flaws.