The Fowler 54-860 Series digital outside micrometer has a ball anvil and flat spindle, a choice of measuring range, and an LCD with an inch/metric switchable resolution for measuring the inside diameter of sleeves, collars, tubing, and other curved and cylindrical surfaces. The ball anvil contacts the inside curve at a single point, providing accurate measurements. Carbide measuring faces provide wear resistance. A switchable resolution of 0.00005" and 0.001mm, and an accuracy of 0.0002"/0.005mm provide precise readings and accurate measurements. A ratchet thimble provides smooth and repetitive operations, and is suitable for one-handed use. Ratchet-style thimbles stop turning when the spindle comes into contact with the work piece, providing constant force for consistent measurements between operators. The insulated steel housing provides durability and is ingress protection (IP) certified IP54 for protection against dust and water. The micrometer can be set to take absolute or incremental measurements. Absolute measurements provide the total dimension of the work piece. Incremental measurements provide a reading that shows the difference between a set standard and work piece being measured. This Type of reading is often used to determine If a work piece falls within tolerance levels. Rs-232 output transfers data to a computer (cable not included). the micrometer requires a CR 2032 battery (included), and includes a fitted case. Micrometers 2" and above include a standard. Comes with full one year warranty on material and workmanship. Contact Fowler directly for warranty claims. Fowler high precision, an American company, manufactures inspection and measurement instruments such as electronic indicators, calipers, bore gages, and digital scales. The company, founded in 1946, is headquartered in Newton, MA.