With graphics to match SRAM RED® eTap® components, the PowerdomeX™ is super light, silent, and delivers an undeniable performance advantage. The nine cogs in the cog cluster are machined from a single block of high grade tool steel, increasing stiffness while weighing even less than a titanium cassette. Between each cog is a StealthRing™ elastomer to reduce vibration and noise. Cutouts on the rear cog further reduce weight and add stiffness. It's the final piece in the drivetrain puzzle, and paired with a SRAM RED® rear derailleur, it delivers ultra-fast, ultra-quiet shifts that will always put you in the right gear.