Park Tool CC-4.2

The Park Tool CC-4.2 is a drop-in chain wear gauge that measures chain stretch across three contact points, accurately indicating 0.5%, 0.75%, and 1.0% wear. It works on 5 to 13-speed chains including modern SRAM T-Type and Flattop designs.

• 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.