There's a hobby called "locksport" where people pick locks for fun. Several of those people post to YouTube and among the most talented is a man who calls himself The Lockpicking Lawyer. He recently posted a video on why not to use a TSA approved lock on anything but luggage but it applies equally well to chastity. I have a little Master TSA approved lock that I briefly used for my crappy CB-6000 clone. I grabbed a dental pick I happen to have handy and not even using a tension tool opened the lock in about 4 seconds. The simple reality is that any of the little locks likely to be used for chastity, even those without TSA approval, are about as secure as a paper clip. Anyone requiring evidence of tampering should probably look to some kind of plastic or metal security seal.
Those locks with the internal locks like the one in your profile pic are just as easy to pick. Unless the one that I have has seized up, it is literally only 1 pin.
Any of the small locks likely to be used for chastity just aren't going to be that pick-proof. A manufacturer isn't going to invest the time/money into a product that could be so easily cut off. The Chinese "magic locks" are basically junk. I think someone makes a "premium" magic lock but I doubt it has any security pins. This is the kind of lock anyone serious about chastity should be using...
A security screw isn't much of a deterrent because bits to open them are pretty easy to find unless you get to a specialized head style like the ones Steelwerks uses. If the you or the keyholder is really worried a seal of some sort is a much better idea.
you can use a tiny eye glass screwdriver to open the specialized heads same with steelwerks Ive done it before when I had one of their devices you could also vibrate it and the screw would come loose. chastity is all in your head you have to be dedicated and devoted for it to work otherwise its easy to break out of.
I completely agree Rus, there's a lot of self control that has to go along with this kink. I think some enjoy the idea of "complete" security, even thought it isn't necessarily the reality. But then again, I think there are a few about living in a fantasy world anyway.