Dynamic Chain Engagement (DCE) is used to hold the chain & help prevent chain jump out. This is achieved by using a broader & taller tooth profile in conjunction with a special hooked leading edge & alternate profiled tooth shaping. This provides superior chain retention lower driving sound increased durability & drag to a minimum. Durable teeth using a plated steel construction supported by a composite carrier body Dyna-Sys 11 HG-X11 11-speed chain compatible Available in 30T/32T/34T