Shimano RD-M591-L 105 10SP
The budget-friendly Shimano 105 Rear Derailleur gets an update for better compatibility with wide range cassettes. This 5701 model now wraps up to a 30t cog in both the short and mid cage versions, so you can conquer the hills with ease.
Like its predecessor, this newest 105 derailleur borrows features from Dura-Ace and Ultegra for crisper shifting even under load. A wider outer link offers increased stiffness for more precise gear changes and greater durability, and Shimano's large 11-tooth pulleys with sealed bearings run smoother and quieter than ever. Compatible with all Shimano 10-speed shifters.