These are stoppers for bundling cables, etc. Made of plastic: polycarbonate, ABS resin. There are 5 packs of 5 pieces each, for a total of 25 pieces. They are useful in various situations in daily life. Not to be dramatic, but once you use them, you won't be able to live without them. [How to Use] 1. Use the pad of your thumb to press the protruding part above the logo, and pull the lever with the unevenness called the "jaw" away from the insertion hole. 2. Place the items you want to bundle between the jaw and the hinge that is screwed in. 3. Insert the jaw back in place and tighten it with a clicking sound, and the items you want to bundle will be secured. Compared to things like "nejiricco" (twist ties), they are easier to bundle, so they are very convenient. They are very tough, and I have never known them to break even after repeated use. The seller attaches them to a backpack strap and hangs a folding umbrella from them. Thank you for looking.