The clasp has a relatively simple locking mechanism that keeps it closed, preventing the clasp from being opened or itself accidentally opened and you could potentially lose your trousers. In theory, this is a great idea, but the way this manufacturer implemented it just doesn't work. Due to the design, the clasp closes so tightly that it is very difficult to open. It takes a lot more force to unbuckle the strap than you would expect. No need to demand the equivalent of opening a stuck pickle jar every time I want to unbuckle my belt. I tried bending the tabs a bit (metal is cheap stamped metal) with needle nose pliers and that worked, but then the clasp didn't line up and the zipper didn't close properly. After playing around with this thing for a good half hour, I decided to return it and get something else. It's just not worth the headache. Shame as I liked the color of the metal and belt, the canvas webbing was well made and taut, and everything else was great. But if the key part of the belt doesn't work well, it's useless.