microSHIFT ADVENT X Rear Derailleur - 10-Speed, Medium Cage, Black, With ClutchWith a raceworthy weight and the right gearing for any situation, microSHIFT's top of the line ADVENT X rear derailleur delivers high end performance without high end headaches. By using a 10 speed chain and wide range 11 48t cassette with predictable, evenly spaced gear steps, ADVENT X allows you to find the right gear even in challenging conditions. Add in microSHIFT's proprietary ratchet and pawl clutch, larger pulleys with taller teeth for better