Narrow Wide tooth profiling ensures ultimate chain retention. Composite material provided by EMS Swiss, with 40% glass-fiber mixture. RollerBoys equipped with low friction ceramic bearings for ultra-smooth glide and exceptional durability. Lubricated with special ceramic light oil for extra smoothness. BDP-16
Compatible with Shimano 9, 10 and 11-speed (except RD-7900 and 7970) / Mega Range, SRAM X0/X9/X7, Apex, Rival, Force and Red (> 2011) and Campagnolo 11-speed.