The Shimano HG901 Dura Ace 9000 / XTR M9000 11 Speed Chain is a super narrow lightweight 11-speed HG-EV asymmetrical design chain for smooth shifts & maximum durability. The outer plate design has been developed to reduce the chance of chain suck & Sil-Tec surface treatment technology (PTFE plating) on Zinc Alloy inner & outer links & rollers makes sure the chain stays running smooth & increases durability. Hollow pins featured throughout the chain mean maximum weight savings. The inner plate has been developed for better contact with gears providing smoother shifting under high load, giving efficient pedalling, increased rigidity & near silent running. This chain has a total width of 5.62mm, optimised for 11-speed Super Narrow HG-EV drivetrains to give its full potential.