Dial Test Indicator & Universal Magnetic Base Set Dial Test Indicator Features... Range: 0 - 0.030" Reading: 0-15-0 Contact Point: 0.080" dia. X 1/2" long Graduation: 0.0005" 2 dovetails: 3/8" and 1/4" dia. Certificate of Calibration . Magnetic Base Features Two universal ball sockets permit adjustment to any angle or position with full 360?ø movement. Fine adjustment clamp. Dovetail and 1/4" holes for test indicators. Knurled knobs and lock screws.