The Fowler 52-246 series outside micrometer has a digit display with a choice of measuring range, 0.00001" graduations, and a blade-style anvil/spindle pair to measure groove diameters of shafts and workpieces with narrow or recessed features. The digit display has 0.0001" graduations and an accuracy of 0.0002" on 1" and 2" models for precise readings and accurate measurements. The positive locking lever on the spindle locks measurements in place for accurate readings. A non-rotating spindle keeps workpieces stable during measurements. Hardened, ground, and micro-lapped measuring faces provide wear resistance. The hardened, ground, and lapped spindle thread provides smooth movement, accuracy, and long life. A friction thimble applies constant force for repeatability between users. Friction-style thimbles are suitable for one-handed operation and stop turning when the spindle comes into contact with the workpiece, providing constant force for consistent measurements between operators.

Micrometers are precision measuring instruments that use a calibrated screw to measure distances. These measurements are translated into large rotations of the screw that are then able to be read from a scale or a dial. Micrometers are typically used in manufacturing, machining, and mechanical engineering. There are three types of micrometer: outside, inside, and depth. Outside micrometers may also be called micrometer calipers, and are used to measure the length, width, or outside diameter of an object. Inside micrometers are typically used to measure interior diameter, as in a hole. Depth micrometers measure the height, or depth, of any shape that has a step, groove, or slot.

The Fred V. Fowler Company manufactures inspection and measurement instruments such as electronic indicators, calipers, bore gages, and digital scales. The company, founded in 1946, is headquartered in Newton, MA.