BBB BDP-06 Rollerboys Jockey Wheels Replacement jockey wheels in a 12t version manufactured from a composite material. Key Features Narrow-Wide tooth profiling ensures ultimate chain retention Composite material provided by EMS Swiss with 40% glass-fibre mixture RollerBoys equipped with low friction ceramic bearing for ultra-smooth glide and exceptional durability Lubricated with special ceramic light oil for extra smoothness 12t compatible with SRAM Rival 1, CX1, Force 1, X1, XX1, X01, GX1