SRAM XX1 XG 1199 X Glide 11 Speed Cassette. SRAM pulled out all the stops in their flagship XX1 1x11 speed groupset, and the XX1 XG 1199 X Glide 11 Speed Cassette certainly is a well engineered marvel. Ranging from 10 to 42 teeth, the X DOME delivers an incredibly wide gear range while maintaining even, optimized steps all in an incredibly lightweight, precise and strong cassette. The single unit cassette combines with the XD driver body for a superior connection to the wheel. The XD driver body is a new cassette driver body design that allows the use of a 10 tooth small cog and provides an improved interface with the cassette. Additionally, the open design aids in mud clearance, giving you a cleaner shifting performance and longer component life.