I was searching for a straplock printable model, but this one (http://www.thingiverse.com/thing:1320905) was way too thick to be used. I bought ones, some time ago, that worked the same way, but it was cheap stuff and the central part couldn't turn well and got stuck, so it wasn't usable either, although the principle seemed good. So I re-made one using the same principle, and making sure it has the right height, and the moving part actually moves correctly. Used it on an actual guitar strap, and it works fine. :) By the way, if you're into guitar stuff (I actually play the bass), you might also be interested in my bass pick : http://www.thingiverse.com/thing:841228 ;)