These locks can't be used with the guitar's original screw. I wouldn't recommend using them with an expensive guitar as the different screw may not fit as well as the original and damage the guitar's screw hole. I couldn't attach the locks the strap. The part that goes through the strap hole is very wide and you may need to cut through the strap to make it fit through. Otherwise the build quality looks good and there's no reason to believe these will come off accidentally.