SRAM RED AXS Rear Derailleur Pulley Kit - 12t Upper and 14t Lower, Ceramic Pulley Wheel Bearings, E1Original equipment rear derailleur pulleys for SRAM rear derailleurs. Ceramic pulley kit includes: 12t Upper Pulley, 14t lower metal spider pulley, 18. 5mm and 12. 8mm titanium pulley screws, grease Compatible with SRAM model: RD RED E E1 Item Specifications Drivetrain Speeds 12 Fits Brand SRAM SRAM Pulley Assemblies Pulley Assembly UPC: 710845911415