Hornady Vernier Ball Micrometer - With a ball anvil and chamfered spindle, the Vernier Ball Micrometer is ideal for accurately measuring case neck thicknesses up to 1-inch within an accuracy of 0.0001-inch. Spindle Lock Preserves Measurement When Removing Cartridge Case From Micrometer Ratchet Stop Ensures Uniform Pressure For Measurement Repeatability Plastic Storage Case Protects Micrometer When Not In Use Baked-Enamel Finish On C-Frame Provides Durability