Humboldt H-2938 Concrete Micrometer
Designed for accurately measuring diameters of concrete cylinders, micrometer has spindles of hardened steel. Thimble and sleeve sections are chrome finish and have black graduations and numbers. The H-2938 has a range of 5.5" to 6.5" and the H-2938M has a range of 150-175mm. Readings can be made to hundredths or thousandths in decimals.