With a ball anvil and chamfered spindle, the Vernier Ball Micrometer ideal for accurately measuring case neck thicknesses within an accuracy of 0.0001 inches. Features: Ideal for accurately measuring case neck thicknesses Measure from 0 to 1 inches with accuracy within 0.0001 inches Ratchet stop ensures uniform pressure for measurement repeatability Spindle lock preserves measurement when removing cartridge case from micrometer Baked-enamel finish on C-frame provides durability Plastic storage case protects micrometer when not in use