These are special clamps that help to align and connect cabinets together. There are two of them in the set - just enough to fix a couple of cabinets at the same time. They are professional, even if you're not a pro at installing furniture, you'll do just fine with these clamps. They are suitable for most types of cabinets. Made of sturdy steel that won't rust, there's an aluminum alignment plate - it helps align cabinet faces perfectly. There is a built-in drill guide, the guide itself will indicate where to drill. They are very easy to use, even if you've never installed cabinets before, you'll be able to do it quickly and easily with these clamps. Suitable for racks from 3.8 to 5 cm thick, the maximum distance between the clamps is about 13.5 cm. Special felt pads are included to prevent scratching of materials during installation.