I bought a couple practice locks. One was, and still is, impossible. However, this one succumbed to a strange trick I made up. Go figure. Thank heavens too. If my first locks were impossible then I might have given up. Here is the very first lock I picked, and it is even a 6-pin tumbler.
I'm an applied-math-research Ph.D. and serial startup founder. I am a recognized computer security expert, fortunate to join the ranks of many, great CTO's. I've founded and seed-funded multiple, successful, VC-backed companies. I'm still at it!