Tool Park Tool CC-4.2 Chain Wear Checker Keep chain wear in check A drop-in style gauge that measures bicycle chain wear. The Park Tool CC-4.2 Chain Checker accurately measures a long section of chain and comes in contact with the chain in three places, taking the guesswork out of judging chain wear. The tool works on any 5 to 13-speed chain or single-speed chain and is designed to indicate when a chain reaches 0.5%, 0.75%, and 1.0% wear. Key Features Replacement guidelines - Two-sprocket (single-speed) chains: replace chain at or just before 1.0% Replacement guidelines - 5-to-10-speed chains: replace chain at or just before 0.75% Replacement guidelines - 11-to-13-speed chains: replace at or just before 0.5% Specifications Part Number 5332632 Color Silver/Blue Size One size Model Year 2026 Weight 86.2g Material Components Steel