Feature? Application & Accurate Measurements? The bore gage features a dial indicator with a graduations of 0.0005″ and a measuring depth of 9.5″, and has a measurement range of 1.4 to 6. Directly replace part for 52-646-400-0? Superior Quality? The dial bore gage anvils are made of high quality carbide, extending wear time and improves wear resistance. Hole gauges are easily adjustable and self-centering for fast, accurate measurements. Reliable Performance? Accurately measuring hole diameters & detect geometry abnormalities, measure the interior diameter of a hole at any depth (within its reach).