The undisputed chain champion. Decades of Japanese engineering and refinement have brought you the most technologically-advanced chain Shimano has ever delivered. Designed specifically for today's 11-speed systems, this Dura-Ace / XTR chain uses an asymmetric layout for better performance and better shifting performance. The chain also runs very quietly, because it has been coated with SIL-TEC, a new Shimano fluorine-based metallurgic surface treatment which decreases friction and increases chain life. Not only that, but SIL-TEC holds onto your lube better and longer, leading again to better chain performance. Finally, Shimano has added hollow pins to shed that extra weight, and included an extra quick link. When it comes down to chains, details matter. Why not put the best on your bike? It deserves it.