Product details:

Count on Keson Fiberglass Tape blade refills for the strength and accuracy you expect on your job. 1/2" Wide, top-quality, nonconducting fiberglass tape blade refills won't shrink or deteriorate. Easy-to-read permanently bonded graduations. Designed to withstand more wear and tear than any other kind of measuring tape! Given the roughest treatment possible... trampled underfoot, beset by mud, dust or rock abrasion, Keson fiberglass tapes go on abuse with little or no deterioration to their tough coating. For use with Keson brand measuring tapes only.