Shimano 105 5800 hg601 11 speed road chainsuper narrow lightweight 11 speed hg ev symmetrical design chain for smooth shifts and maximum durability features outer plate design has been developed to reduce the chance of chain suck sil tec surface treatment technology ptfe plating on inner links that is smooth running and increases durability the inner plate has been developed for better contact with gears providing smoother shifting under high load giving efficient pedalling increased rigidi