Engineered to deliver performance unequaled by any other file, for use on ultrahard materials. Carbide, hardened steel, exotic metals, ceramics, and glass are no match for these precision files. Excellent material removal is the result of a unique process that bonds the 2-1/2" (64mm) long diamond surface. Overall length is 5-1/2" (14cm). 5 Pc. sets include Equalling, Round, 1/2-Round, 3-Square, and Square.