I recommend the Spydercard, its what I carry. Be sure to look over the lock. I took the time to experiment with mine and found that I could overpower it with my hands, but it took quite a bit of effort. It doesn't concern me that much because I use locks mainly to just keep the blades open, I don't trust that many of them to take an impact (even though my s2k is supposed to) I kinda treat them like slip joints. And it a wallet knife, so I gues I can only expect so much, but its been handy and reassuring to have it there.