I have purchased many guitars in my lifetime because I own a music school. Dunlop makes great products and these are amazing. Strap locks prevent your guitar from slipping off of the strap by creating a locking system with your guitar strap. It does take some work to get the straps to lock, but with some pliers and a youtube video, you can figure out how to attach these to your guitar strap. I would purchase another set when needed and I recommend these to my students.