I have used these inexpensive locks on my concert guitars for years and never had any problem. They are especially effective on my dreadnaught Guilds and Ovations. I have bought several and given them to friends who have asked what I use and none of us have had any problems with them. I like the fact that I can put them on and take them off easily and can use them on different guitars. To date I have not had any fail or break, but I don't do "stunts" with my guitars, either. (Not knocking those who do - just making the point that I don't and that might make a difference.) I use a Planet Waves strap with built-in locks for my Fender LIII and Guild DeArmond and Planet Waves Quick Release Attachment (and these locks) for my Guild 12-string and Guild D-25, since they don't have front buttons. I haven't had any problems with any of these items in the years that I have been using them. I do use a set of Straplok®s on my Bluesbird.