Chain Checker is a drop-in style gauge that measures bicycle chain wear.
Accurately measures a long section of chain and strategically comes in contact with the chain in three places, quickly and easily taking the guesswork out of determining when chain replacement is necessary.
Works on any 5 to 13-speed derailleur chain (including SRAM T-Type, SRAM Flattop, Shimano XTR 12-speed, and Campagnolo Ekar 13-speed chains) or single-speed chain, and is designed to accurately indicate when a chain reaches 0.5%, 0.75%, and 1.0% wear, the points at which most chain manufacturers suggest replacement.