Product details:

Outside micrometer with a 0 to 3" measuring range and flat anvil/spindle pair for general purpose measuring, set of three Vernier scale has 0.0001" graduation interval for precise readings Hardened and precision-ground anvil and spindle have 0.256" diameter micro-lapped carbide measuring faces with 0.00005" parallelism on 0 to 1" micrometers and 0.00003" flatness for accurate measurements Friction-style with ratchet stop applies constant force for repeatability between users and is suitable for one-handed operation Insulated frame helps reduce temperature-related expansion or contraction and isolates heat from the operator's hand .0001" reading (.01mm on metric set). Ratchet thimble and locking nut. Microfine graduations. Sizes over 1" include standard. Meets or exceeds Federal specifications.