My guitar came with a set of these when I bought it. The locks themselves have an opening that go in from one angle, so if you are trying to change guitars quickly, it will be difficult to get the strap on and off, especially in the dark. Also, I've almost dropped my guitar because the nut that attaches the locking part to the strap worked its way loose after a while and the whole thing came apart while I was playing. Fortunately, I had one hand on the guitar and was able to catch it. I have a set of Dunlop Straploks on my other guitar and have never had a problem with those. I will be swapping the Schallers out with a set of those.