Shimano dura acextr hg901 11sp sil tec chainsuper narrow lightweight 11 speed hg ev symmetrical design chain for smooth shifts and maximum durabilityfeaturesouter plate design has been developed to reduce the chance of chain sucksil tec surface treatment technology ptfe plating on inner and outer links and rollers that is smooth running and increases durabilityzinc alloy plated inner and outer linkshollow pin for added weight savingthe inner plate has been developed for better contact with g