SHIMANO XTR RD-M972 Shadow Rear Derailleur GS 9 Speed Top Normal, Long Cage

M972 'Shadow': lower profile body with direct cable routing, stronger spring, and redesigned bracket to avoid chainstay contact (carbon cage and aluminum B-attachment with a Top-Normal return spring). M971 Traditional: Top-Normal return spring ideal for RapidFire. M970 Rapid-Rise: Low-Normal return spring ideal for DualControl. Wide link parallelogram design increases rigidity and performance. P-body rubber bumper reduces noise and adds durability (M971/970). 4 flouric coated link pivot bushings minimize friction. Aluminum construction with sealed bearing 11 tooth pulleys.