SHIMANO XTR RD-M980 10 Speed Rear Wheel Derailleur Trail-tuned XTR 10-speed, rear wheel derailleur with low profile Shimano Shadow design Top normal spring design to mesh with Rapid-fire shifters for trail/all-mountain riding Main body spring tension works well with full outer casing and creates more consistent shift effort throughout the entire cog range Carbon fiber outer pulley plate for lower weight and aluminum inner pulley plate for rigidity and durability Sealed bearing guide and tension pulleys; 3-year warranty