Features Mechanical tubular-rod inside micrometers use interchangeable hollow and lightweight rods to measure the inside dimensions of holes, tubes, pipes, cylinders, rings, and other parts. The measurement is taken on the vernier scale. Range / 2 inch to 12 inch Resolution / 0.001 inch SPC Output / No Movement of Screw / 1/2 inch Inside Micrometer Type / Tubular Inside Micrometer Number of Measuring Rods / 5 Number of Micrometers / 1 Operation Type / Mechanical Thimble Type / Plain Case Included / Yes Case Type / Wood Case Contact Point Material / Steel Contact Point Shape / Flat/Curved Features / Carbide Contact Points Includes / Adjustment Wrenches, Rods Lock Nut Type / Positive Maximum Measurement - Inch / 12 inch Minimum Measurement - Inch / 2.0 inch Rod Diameter / 0.61 inch Rod Lengths Included / 0.5 inch, 1 inch, 2 inch, 4 inch Spindle / Curved Accuracy / +/-0.00005 inch