Hi-Performance Extremely Durable Bulls-Eye pin: The unique KMC bulls-eye pin riveting provides unsurpassed side plate retention. X-SP treatment: KMC's extreme stretch-proof treatment of pins and plates makes this chain less susceptible to wear caused by sand or other exterior material invading into the chain bearings. Drastically enhancing durability. High alloy material: Pins and plates made out of special alloy material reduces chain stretching and thus prolongs chain life. X-Bridge: The x-bridge outer plate has been configured with precisely articulated angles for quicker and smoother gear shifting and quieter riding. 1/2' X 3/32' - 114 Links pin length 7 3mm Compatible with: 18-21 24 speed HG Half Nickel plated