X01 HollowPin 126 links with PowerLock 12 speedIt 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-chainring drivetrains. And its also the biggest contributor to the Eagle drivetrains ultra-smooth, precise, durable and quiet performance. The Eagle chains links have a smooth radius, with no sharp edges or chamfers, which yield a significant reduction in noise, friction and wear on chainrings 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 chains optimal performance life, and a Titanium Nitride coating on the Gold and Black models decreases corrosion and further reduces friction.