Take a quick look at the new X-DOME™ Eagle™ cassette. The last dangling shred of an argument in favor of a mountain bike front derailleur is now officially dead.Designed for use with our proven, reliable XD™ driver body, this 12-speed, 10- to 50-tooth cassette offers an optimal 500 percent gear range at a considerably lighter weight than 2x systems. It carries with it the X-DOME™ architecture, which, independent tests have concluded, yields the strongest cassettes on the market. New shifting characteristics improve both, inboard and outboard shifting, as well as chain retention.Features : SRAM's cassette manufacturing technology provides the greatest durability and lightest weight All-new shifting features create a smoother, quieter system with enhanced inboard and outboard shift performance XD™ driver body compatible 10, 12, 14, 16, 18, 21, 24, 28, 32, 36, 42, 50 Weight : 355gTechnologie : X-DOME™X-DOME technology creates an incredibly lightweight, precise and strong cassette. The open design aids in mud clearance, giving you cleaner shifting performance and longer component life. X-Glide 2X-GLIDE™ 2 is next generation of SRAM X-GLIDE™ technology optimized for the EAGLE™ 12-speed cassette. It provides quick, precise, power-on shifting performance throughout the gear range, and increases chain retention on larger cogs. XD™ Driver BodyXD 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.