On his YouTube channel, Applied Hacking, Samy Kamkar has posted a series of clever and devilish Master combination lock hacks. In this installment, he shows how easy it is to manually defeat a lock with little more than some fiddling with the dial and entering the results into an app that he’s developed. Using this technique, he is able to pick the lock in the video in only four tries. Rather disturbing if you use one of these locks to secure anything. Let’s hope Master is taking notice.

In a subsequent video, Kamkar takes a lock apart to show you how it works and what the exploits are. And in another, he builds a mechanized lock-picker that can defeat a combination lock in seconds.