Digital tubular-rod inside micrometers and sets are used to measure the inside dimensions of holes, tubes, pipes, and other parts. These micrometers are used with interchangeable tubular rods that are hollow and lightweight. They are connected to the micrometer and inserted into bore holes or openings. The ratchet thimble on the body of the micrometer is adjusted until the rod makes contact with the surfaces being measured. When the micrometer is locked and extracted from the hole, the user reads the measurement on the LCD display. These digital micrometers are easy-to-read and do not require operators to do any math. They are commonly used by mechanics and machinists in large diameter applications.