102-301 is an outside micrometer with heat Ins. plate. It is a basic, cost effective, non-digital micrometer. It has cutaway frame behind anvil helps measurement in confined spaces. The highly stable frame incorporates a heat shield to preserve accuracy over extended measuring sessions. A ratchet stop guarantees repeatable measurement. Analog, 0 to 25mm range, 0.01mm graduation, ±2µm maximum Permissible Error J MPE Accuracy is ±2µm, 0.6µm flatness, 2µm parallelism With spindle lock, ø6.35mm, spindle pitch 0.5mm measuring spindle Thimble and sleeve satin chrome finish, ø18mm scale