Designed to work with the tight tolerances and narrow profiles of 10 to 12 speed chains but also works on all other derailleur and standard 18rdquo width single speed chains the park tool ct 43 is a powerful precise tool designed to quickly and accurately remove and install chain rivets without a doubt the most accurate chain tool wersquove ever built park tool ct 43 master chain tool with peening anvil features park tools latest pro level chain tool is now updated to wo