OE Replacement pin for the Shimano CN-7801 chain but works with all Shimano 10 speed chains, including the CN-6600. A must for the well stocked tool box or home shop. Easy to differentiate from 9 speed pins from the markings on the side of the pin. For use with Shimano 10 speed chains only. Not compatible with the original and long-ago discontinued CN-7800 chain. Install with 10 speed chain tools only.