Sharing XX1 technologies, like X Horizon, Roller Bearing Clutch, and Cage Lock, the X01 DH 10 Speed Rear Derailleur will provide race winning performance. This downhill focused product works with the X01 10 speed shifters and cassette for system that's dialed specifically for the needs of gravity riders. X Horizon limits the movement to the horizontal axis, making ghost shifting nonexistent and an offset upper pulley wheel provides a constant chain gap through all gear ratios. And with the combination of the X SYNC pulley wheels, and a Roller Bearing Clutch, the chain is tensioned with the derailleur and locked in place with the pulleys, effectively making dropped chains and missed shifts things of the past. The Cage Lock technology also adds convenience to bike maintenance, too. While either installing a new chain, swapping tires, or changing a flat on the trail, you're able to lock your derailleur in place for easy adjustments. Just push the cage forward to create some slack, and lock it into place while you work on your bike. No extra tools are required to make this happen, which makes trail emergencies where you need to remove your wheel a simple fix. Sram's X01 DH 10 Speed Rear Derailleur is available in the colors Black and Red and is only compatible with X01 DH components.