Odyssey Bluebird Chain - Single Speed 1/2" x 1/8", 112 Links, BlueOdyssey Bluebird chain is the proven and reliable KMC 510 HX chain with an added a permanently attached, factory installed half link to one end. When the chain is trimmed to size you can easily decide whether or not to use the half link. Original factory assembled pin joints are radically stronger than workshop assembled ones, so this is a huge benefit. Proven and reliable KMC 510 HX chain Factory installed half link for a radically stronger set up