Dura-Ace rear derailleur with lightweight carbon cage and wide link design gives quick accurate shifts, and unmatched drivetrain efficiency-Full carbon fibre inner and outer pulley plates enhance rigidity and significantly reduce weight-High tolerance cold forged aluminium link plates and body construction provide for extremely light weight, strength and durability-High rigidity wide outer link plates the pulley body to increase pivot joint rigidity-Sealed pulley bearings reduce friction and rotate silky smooth increasing efficiently-Four self-lubricating micro-machined fluorine-coated link pivot bushings provide low-friction shifting-Pulleys are made of tough DuPont Zytel for longer life and less chain noise-With a total capacity of 33 tooth, it is able to operate with wide gear ratios up to a 28 tooth cassette sprocket-Hard wearing Dura-Ace finish and graphics for long lasting good looks-10-speed compatible-Weight: 166 grams