Designed by designer Jess Han the Numlock Handle is an innovative solution for those of you who want to enter your home without using keys. 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. The idea is good especially if you have a room where you want to keep some valuable things, but to time consuming for the front door ( especially if you are in a hurry ). – Via – Dvice