The Crescent 1/2" x 100' Fiberglass Tape Measure, part FE100. It has a fibreglass handle that absorbs shock and will not dry out. Supplier specification: TAPE FBGL 1/2"X100' OPENREEL.
An open-reel tape is for distances a pocket tape cannot cover. Fibreglass is non-conductive and will not rust, which is why it is specified for electrical work and for anything wet or outdoors — a steel long tape is more accurate but conducts and corrodes.
