INSIZE Blade Micrometer The anvil and the spindle have a blade for measuring the groove diameter of shafts, keyways, and other hard-to-reach portions. Specifications include... 0.0001" Graduations Accuracies... 0-2": 0.00015" 2-4": 0.00020" 4-6": 0.00025" 6-10": 0.00030" 10-12": 0.00035 Select Measuring Range from Pulldown List Features include... Ratchet Stop for constant force Supplied in fitted case Blade Dimensions... 0.030" Wide 0.236" Tall 0.256" Long