CeramicSpeed pulley wheels reduce friction, last 3-5 time longer than stock high-end pulleys, and are designed to work with less drag. FEATURES: Premium Grade 3 Silicon Nitride Ceramic balls Hand built in Denmark Precision machined aluminum narrow-wide pulleys Hardeneed Races Includes: (2) 12 tooth pulley wheels, Alloy Spacer Kit and CeramicSpeed Bearing Oil 15ml bottle Compatible with SRAM Red AXS, SRAM Force AXS, SRAM Rival AXS, please note these pulleys are not compatible with any XPLR derailleurs SPECS: Fits Brand: SRAM Drivetrain Speeds: 12