This Lufkin 20-foot engineer's Artisan?? tape has a Chrome Clad?? Nubian?? blade in a rugged steel case with vinyl covering, featuring a large easy-action winding drum and friction washers. The nylon roller guides the tape smoothly in and out of the case. The B10-style blade is 3/8ths of an inch wide and 0.008 of an inch thick with graduations in feet/tenths/hundredths on one side, and in diameter feet and inches to tenths on the other. The "T" prefix denotes a tree tape which is fitted with a special claw hook designed for anchoring in tree bark, and the "P" prefix denotes diameter graduations.