When designing this rear mech, SRAM paid particular attention to the finer details such as refining the jockey wheel tooth geometry & upgrading the anchor bolt to a hollow titanium. The result of this is that the chain runs through the mech smoothly & almost silently. In addition to this, SRAM used its Exact Actuation technology, which offers a simple set up process & slick, accurate shifting. Technologies: Aero Glide Pulleys: New tooth pulley design with a sound damping effect for a super efficient & silent ride experience. Bottom & top pulleys benefit from this feature. Exact Actuation: When SRAM launched their road technology from scratch they reapplied their MTB proven SRAM 1:1 actuation ratio (shifter cable travel: derailleur movement) for 10 speed rear shifting. EA helps to simplify/stabilise the uneasy act of balancing rear derailleur hanger design, tight cog spacing & exact cable tension. The result: the easiest index shifting system to set up & it stays that way.