Applications include measuring wall thickness of cylinders and tubes, shoulder to edge distance, rivet head height etc., accomplished using the: standard flat anvil, rod anvil, or optional V-anvil. Easily interchanged, with constant force ratchet and positive locking clamp. Quick and easy zero adjustment. Interchangeable anvils supplied: Flat anvil (201216). Rod anvil (201217) 3mm diameter for 0-25mm/0-1", (201379) 5mm diameter for 25-50mm/1-2". V-anvil: (201218) Available at extra cost. Accuracy: Flatness: 2mm (Anvil Face), 0.6mm (Spindle Face). Parallelism:3mm. Instrument Error: 4mm.