Park Tool CC-2 Chain Checker The Park Tool chain checker is a precise and accurate way of inspecting your chain for damage, wear and tear. When riding it is crucial that your chain is in tip-top condition, any wear could lead to under performance, and that’s the last thing you need when beating your personal bests. With the Park Tool CC-2 Chain Checker, you can be sure your chain is in race condition. – T.H Key Features: An accurate way to check for wear of roller and pin on chains. 1% of wear is enough to affect chain-rings and sprockets, and allow shifting performance to deteriorate. Just insert the chain Checkers pins into two links, press the swing arm gauge, and then check the gauge window for an accurate reading. Reads wear from 0.25% to 1%. 10-speed compatible.