DIAMETER TAPESThe diameter of a circular object, like a tree or a pipe, is easilymeasured using a Keson diameter tape. The tape is calibrated inunits of 3.14(pi) inches. The tape is actually measuring the tree orpipe’s circumference, but the units on the tape are adjusted by pienabling you to get a diameter by wrapping this tape around acircular object.Our PD618 has a stainless steel case which features a reflectivesurface and textured rubber grip to keep the tape from slipping.Our D18646 features the same blade in a plastic case.