Magnetic Surface Gage and Dial Test Indicator Set Featuring a permanent magnetic base with on / off switch and fine adjustment. Doubles as surface gage when used with magnet turned off. 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 Base: 3-1/8" x 2-7/16" x 1-7/16" 5/16" x 9" post 1 main swivel clamp 2 holding rods: 7/32" x 2-1/4"" and 2-5/8" 1 scriber rod: 7/32" x 4"