Park Tool CC-4.2 Chain Wear Indicator

A worn bicycle chain causes poor shifting performance and accelerated wear on drivetrain components, causing more expensive problems
The Park Tool CC-4.2 Chain Checker is a drop-in style gauge that measures bicycle chain wear
The laser-cut CC-4.2 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
The tool 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
Some drivetrain manufacturers have unique recommendations specific to their components, always double-check to be sure
Made in the USA and covered by Park Tool's legendary limited lifetime warranty