ER25 x 1/4" High Precision Spring Collet. These High Precision Collets reduce the vibrations on the tools and motors; assuring better results, and prolonging the life of the tools, holders and spindles. Maximize life of collets and collet nuts; utilizing collet cleaning brushes and rust and stain remover. Replace collets after 700 to 800 hours of usage. Select tools with the shortest possible cutting length to achieve required depth of cut.