AluBoys Derailleur Pulleys Durable and super smooth Upgrading your bike with little details is so nice to do! The AluBoys will lift your bike to a higher level easily. The aluminium derailleur pulleys are super durable and make your chain roll super smooth. The stiff aluminium keeps the pulleys super lightweight. And after all, they also look amazing on your bike! 7075 aluminium derailleur pulleys Extra stiff for fast shifting High quality sealed ball bearings Part Number: 2913612101 Barcode: 8716683074130 Product Code: BDP-21Compatible with Shimano 9, 10 and 11-speed (except RD-7900 and 7970) / Mega Range, SRAM X0/X9/X7, Apex, Rival, Force and Red (> 2011) and Campagnolo 11-speed.Release Year: 2020