found these to be cheap and made poor quality metal that snapped on one set i bought. the design is ok but let down by the cheap materials used . the part you screw in to lock the holder in place comes loose/unscrews as you play so thats an accident waiting to happen the screws supplied are too small and thin to work so you will have to use different ones. save your money and spend a few quid more on a better one.
Ever since the first time a strap came off my guitar on stage I have always used strap-locks. Having tried several different types I can say without hesitation these are the best for the money. Using them on all guitars means a quick change with your favorite strap. A Must Have!