Groove Micrometer Features include... Flanged spindle for measuring width, bore depth, and location of grooves. Inside Range: 1.05 - 2.05" Outside: 1.0" - 2.0" Disc Dia.: 0.50" Reach: 3.38" Graduation: 0.001"/0.01 mm. Accuracy: 0.001"/0.01 mm. Parallelism: 0.001"/0.01 mm. Certificate of calibration . Furnished in fitted case.