We're always on the lookout for a better way to gain entry into our homes without using keys. Sure, there are fingerprint readers, and all manner of electronic ways to lock your doors, but they're prone to failure. Short of shooting all those who attempt unauthorized entry, what to do? This design concept for a mechanical lock could be the ideal solution to the keyless lock problem.
Numlock Handle is unlocked when you roll its four tumblers to the correct numbers, and then after you've gained entry it automatically jumbles up the tumblers to lock the door behind you. You'll never need to worry about lost keys again, but then there's that challenge of remembering the combination.
One suggestion we'd add: embed a tiny LED inside to backlight the numerals for easier nighttime entry.
Via Yanko Design