Precise & dependable 10 speed shifting performance, Srams X0 rear derailleur is the ideal addition to any 10 speed groupset. A new chassis design helps add versatility to the X0 10 Speed Rear Mech to deal with all weather conditions. Direct Route Heres the dirt on middlemen: they suck. Thats why Direct Route Technology doesnt have one. Instead, the cable routes directly to the actuation mechanism. Result? Less friction. Less effort. More oomph. Plus its impervious to cable housing damage. Nice. Exact Actuation When we launched our road technology from scratch we reapplied our MTB proven SRAM 1:1 actuation ratio (shifter cable travel: derailleur movement) for 10 speed rear shifting. EA helps to simplify/stabilize 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.