This is a Hobbies and Toys video tutorial where you will learn how to use a Micrometer. Micrometers are precision measuring tools and they can be calibrated in inches or in metric system. There are also digital micrometers available where the reading switches back and forth. Generally they are right handed. The micrometer shown in the video is calibrated in inch. Each division is one thousandth of an inch. A whole rotation of the knob is 25,000 and one division is seen on the bell. Two rotations are 50,000 which is two divisions which equals to .05 inches. Rotate further, and a number 1 will be visible. That is .1 of an inch. Then the video goes on to explain the other scale where one division is ten thousandth of an inch.