These little guys are lifesavers for DIY furniture builds or repairs! They're M6 hex socket insert nuts, made from zinc-plated carbon steel to resist rust and hold up over time. Each one is 20mm long (other sizes available too). You drill a hole in your wood, then screw these in with a hex key—the external threads bite into the wood, locking them in place so they won't spin or pull out. They create a strong, threaded socket so you can bolt pieces together securely. Great for assembling shelves, beds, tables, or any wood project where you need a hidden, sturdy fastener. Unlike barrel nuts or T-nuts, you can install these from one side, which is way more convenient. Pack of 20 means you've got plenty for multiple projects. Just make sure your pilot hole is deep enough! If you're tired of wobbly furniture or stripped screw holes, these insert nuts add professional-level strength to your builds. A must-have for any serious woodworker or fixer-upper.