“Wheels On” EZ-Drum Reach Electronic Brake Drum Gauge 4-20/100-500mm capacity (internal measurements). Inch/metric/fraction conversion. 4 drum preset (101.60mm). Floating zero sets zero anywhere. Hold function. Resolution: 0.0005/.01mm/fractions in 1/64th increments. Accuracy: 0.005/.13mm. Dust, water and oil to IP54 standards. RS232 output for direct computer connection. Beam has vernier scale to double check reading. Conversion chart on back of main carriage. Includes 4 setting master. Steel conical contact points. Carriage lock screw. Includes fitted case 74-150-050 Prop65 information pending -