SRAM XX1 Eagle Chain - 12-Speed, 126 Links, Black

It might look normal from the outside, but the engineering inside this incredible new chain design that makes possible a gear range previously found only in 2-chain ring drivetrain. And it's also the biggest contributor to the eagle drivetrain's ultra-smooth, precise, durable and quiet performance. The eagle chain's links have a smooth radius, with no sharp edges or chamfers, which yield a significant reduction in noise, friction and wear on chain rings and cassette cogs. This design also allows for a flatter plate, which means more consistent chain riveting and greater overall strength. Hard chrome technology extends the chain's optimal performance life, and a titanium Nitride coating on the Gold and Black models decreases corrosion and further reduces friction