The Shimano Deore XT RD-M8100/8120 Tension and Guide Pulley Set is for Deore XT RD-M8100-SGS and RD-M8120-SGS rear derailleurs. This product is a Genuine Shimano replacement part.
Best Price: £13.60 from Tweeks Cycles
Shimano Deore XT RD-M8100/8120 Tension and Guide Pulley Set Reviews