Bought this for my Bass guitar as I had my bass slipped off the strap and I was able to catch it before it hit the ground. Bought these strap locks, installed them and have peace of mind. On a side note, the nut is a 9/16" and if you put a 5/8" open end wrench on the other end of the U shaped part, it is fairly easy to tighten this on the strap. This is insurance for your guitar, don't think twice, just buy these.