Big Horn 19680 Miter Clamp Set. Set includes one spreader and 4 clamps each of the 6 sizes listed. Quick and easy to apply made from tempered spring steel, these sharp ended clamps hold by pulling the pointed ends apart to engage. Choose the appropriate size spring clamp and use the spreader to open and position the clamp. Makes clamping miters easier by keeping mitered pieces firmly aligned for gluing or nailing.