Micrometer
A standard micrometer is a screw gauge that is used to perform very small measurements with a very high level of precision. This device is made up of an anvil, a spindle, a lock, a sleeve, a thimble, and a ratchet. The build of a micrometer is such that when an item is placed between the faces of the anvil and spindle, the sleeve (or barrel) and thimble can be adjusted in order to have the item be held between those two faces. Once positioned properly, the sleeve and the thimble can be read in order to find the measurement of the item. The sleeve and the thimble of the micrometer each provide a number that is then added together. Micrometers are incredibly good at what they do, and provide measurements to the thousandths decimal place. Digital micrometers can even report a measurement to the 100 thousandths place. The handy lock located centrally on the instrument allows users to lock the anvil and spindle at the edges of the item being measured, and the ratchet and thimble make for smooth, easy adjustments.