This is the SRAM XG1199 11 Speed Cassette. The SRAM XX1 was built with a dedicated 1X design philosophy – making it simpler, lighter and more durable than any other. No matter where you ride, no matter what you’re up against: SRAM XX1. Unstoppable. 11 Speeds (10-12-14-16-18-21-24-32-36-42). This cassette is machined from one large piece of hardened steel, leading to a high level or precision to the shifting steps. It is one piece with no lose parts, lock rings or cogs. The completely redesigned driver body (not included) has a perfect tight fit connection with the cassette for unmatched load transfer.