Excellent strap-locks. I have them on all my guitars, so I keep one strap for all guitars. A few caveats: after some time, the button won't unlock and you (I) will struggle to take the strap off of guitar. It may be because of the age, dirt, whatever. I didn't noticed anything wrong on the parts, it just doesn't unlock! Maybe the grease inside gets old and sticky and the small balls of the mechanism don't move any longer. Other than that (which is kinda important), they are okay.