Absolute precisionthe rear derailleur with ultra shift geometry is designed to give you the certainty of immediate shifting in all conditionsthe oversized outer plate wraps around the upper and lower bodies of the rear derailleur providing superior stiffness this translates into the absence of play and the maximum speed of chain movement upward and downwardfeatures benefitsultra shift parallelogram designed to wrap around the rear derailleur bodies and increase the overall stiffness of