Shimano Ultegra FC-R8000 External Chainring 11s

External chainringShimano Ultegra FC-800011-speed double-pedal chainring Hollowtech II hollow construction to save weight and increase rigidity for optimal power transfer. New design of the teeth for smoother shifting. Shimano recommend these setting for optimal functionning: 50-34 52-36 53-39 Features: External chainring Construction Hollowtech II Material: Aluminum 4 branches BCD 110mm Compatible 2×11 speeds