Sram: The XX SL Eagle Transmission (T-Type) Cassette is a major reason why Eagle Transmission offers the best-ever inboard and outboard shifting performance under load. Thanks to its full X-SYNC design, the harder you pedal, the better it shifts. Literally. Our lightest Eagle cassette in history lasts far longer and delivers more precision. Its new-gen design is fully machined, hardened steel X-Dome architecture for gears 1-9 and an ultra-lightweight, all-aluminum Spider Cog for gears 10-12. Engineered as integrated and interdependent transmission components, the XX Eagle Transmission Cassette and derailleur contact directly, ensuring perfect alignment on every bike. From its massive 520% gear range, the 52 tooth cog steps down with improved gear progression with 44 and 38 tooth cogs in the low end (compared to the Eagle drivetrain 10-52-tooth cassette). Featuring a clearly marked Setup Cog, install is both simple and fool-proof.FEATURESNew-gen design is our lightest ever 10-52T cassette due to the ultra-lightweight, all-aluminum Spider CogFull X-SYNC for best-ever inboard and outboard shifting performance under load. Optimized gear steps on low end55mm chainline compatibility for more moderate chain angle, longer wear and greater precision. Setup Cog for fool-proof set up. Utilizes well accepted and broadly available XD driverbody SPECIFICATIONSSpeed (CS): 12sGearing: 10-52tCog finish (Cassette): BlackTechnology (Cassette): XSCog sizes: 10-52t:10,12,14,16,18,21,24,28,32,38,44,52Driver body interface: XD