The Starrett Electronic Micrometer Head with Standard Inch Graduations on Shell and Thimble includes 0-1"/0-50mm range, friction thimble, lock nut, and carbide face. Featuring large digital readout that is easy to read and reduces errors. Conventional inch or millimeter graduations are standard. Heads are easy to handle with smooth friction thimble for uniform pressure. 0-1" (0-50mm) Range, Friction Thimble, Lock Nut, Carbide Face pressure.