Accuracy: 1/50th - 0.02 mm. Measurement capacity: 300 mm. Interior, exterior measurement (bore exceeding 10 mm). Stainless steel rule - mat finish. Rule hardness: 40 HRc minimum. Vernier with guide for better thumb position. Vernier endurance: 20 000 cycles minimum. Vernier screw locking. Precision adjustment screw. Supplied in case with compliance certificate.