The best advice I can give you is to buy two more so you have four clamps. The reason is support. Using these clamps will raise your workpieces 3/4 inch off the surface. I have a photo to show you the thickness of the base. Therefore, they are difficult to level with longer boards. Because even if you turn the knob to tighten the clamps, gravity pulls the boards down from the other end, so you'll never get a perfectly square clamp. So you need the same clamps on opposite ends to support and align the workpieces. Alternatively, instead of buying two more, buy something 3/4 thick. It doesn't have to be exact. You just need something to support the opposite ends of the boards so they are as level as possible. Only then can you repair them properly. Each clip weighs 26.3 ounces. They feel like good quality. If you know this isn't for precision work and that it takes extra effort to clamp accurately, then go for it! I think people new to woodworking might knock off a few sprockets, but I've known about them for a long time and have used them before. They're great for projects that don't require precision, like assembling coasters and shelves in your garage with a 2x4. 5 Stars!