When miters are glued up they tend to open at the tips because end grain has been cut on the diagonal. These little spring miter clamps are perfect for keeping the pressure on while gluing miters, and when the glue is dry the tips will still be together. The sharp points pierce the wood without cutting wood fibers so it's easy to clean up the marks.
Miter clamps are the only way you can pressurize compound miters and these clamps will hold any compound miter as well as all awkward shapes and profiles. When you see the superior results, you'll never stop using these clamps.