Abstract: A device measures cylindricity of a cylinder having an axial end, a circumference and an inside diameter. The device includes a track for placement at an axial end of the cylinder to be measured. The track extends around the circumference of the cylinder. A pair of trucks are mounded to the track for movement around the cylinder circumference. A sighting beam generator, in particular, a laser, is connected to each truck for aiming sighting beams axially along the inside diameter of the cylinder. A micrometer adjustment is connected between each laser and its truck for adjusting a radial position of each sighting beam.