12T. Composite material provided by EMS Swiss, with 40% glass-fibre mixture. Narrow Wide tooth profiling ensures ultimate chain retention. Sealed bearings. Compatible with: SRAM. Made of: Grivory EMS.
Best Price: £14.95 from Merlin Cycles
BBB BDP-06 RollerBoys Sram Jockey Wheels 12T – Black / 11 Speed Reviews