These Mini Backpack Clasps can be applied to numerous items and projects. Place them on dog collars as an extra attachment for dog tags, bracelets and other jewelry to hold it together in a loop, backpacks for holding onto small items, or use them when making lanyards and key chains. The 25mm clasps are made of metal and have a hole at the bottom to string cord through or an easy open clasp closing the hook where objects, cord, and other objects can be attached.