CeramicSpeed Pulley Wheel Description: 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 Hardened Races Includes: (2) 14 tooth pulley wheels and CeramicSpeed Bearing Oil 15ml bottle Compatible with Shimano XT M-8100 series and Shimano XTR M-9100 series Specifications: Compatibility: Shimano XT/XTR Speeds: 12 Speed Color: Black