Shimano Shimano Deore M591 SGS rear derailleur

9-speed compatible Shimano Deore rear derailleur in Wide Link design. The derailleur body guarantees improved firmness with precise shifting performance. The patented Shimano Double Servo-Panta mechanism keeps the read derailleur guide pulley at a uniform and constant distance from each sprocket. The results are light shift efforts with smoothly changing gears.Top-Normal shifting system optimized for use with Shimano Rapid Fire shifting levers.