GOOD LONGEVITY: Micrometer main body is made of stainless steel, chrome plated surface, wear resistant and durable, so it is able to maintain high precision for long time use.HIGH ACCURACY: Heat insulation frame, unique design allows you to make quick measurements with one hand; High quality alloy measuring heads can be used for different internal size measurement, fine workmanship with careful polishing, no burr at all.WELL-DESIGNED: Designed with locking device, precise machine structure makes it more intuitive and convenient to operate, clear marking line makes it convenient for reading, built-in ratchet stop device ensures accurate repeat readings .Useful Tool Set: Supplied with a useful adjustment ring gauge and a small spanner for the micrometer, but please note that the micrometer does not need adjustment unless it is very worn.Storage Case Package: Comes in a quality wooden case with soft foam liner protection, ensure the inside micrometer is high precision and in good condition.