Not feeling secure with that deadbolt lock on your front door? Check out the Numlock Handle. Designed by Jaeseok Han, the Numlock Handle features a number-combination lock that prevents “unauthorized” access to a room (or building). The door handle does not turn unless the correct four-number combination is entered. Good luck opening the door in an emergency.
Secure? Probably not (brute force, anyone?). But, the coolest feature of the Numlock Handle is its ability to automatically lock itself by shuffling the numbers after each successful door entry. Plus, you can easily change the combination and even replace (or supplement) the numbers for braille. So, what happens when you forget the combination? No idea. Hopefully, if the Numlock Handle ever enters into production, there will be a master key to unlock the handle in emergency situations .
Just make sure no one is looking over your shoulders as you enter the combination.
Via: Yanko Design