The Crescent Lufkin W606 EXECUTIVE Diameter Tape is designed for measuring diameters of pipe, cable, tyre or any circular object. It has a yellow-clad tape with easy-to-read bold graduations. Zero falls in the same place on each side of the blade. A spring-action returns the blade to the polished chrome case. Model W606PD shows diameter inches to 100ths, W606PM to millimetres.