Shimano ultegra 6800 11 speed rear mechultegra rear derailleur with wide link design gives quick accurate shifts and excellent drivetrain efficiency features wide outer link plates increase pivot joint rigidity to reduce shifting deflection lightweight aluminium pulley cage helps reduce weight without sacrificing shifting performanceshort cage specifications intended useroad cassette compatibilitycs 6800 maximum sprocket28t12t minimum sprocket23t11t maximum front difference16t tota