Strong as steel, light as aluminium.
Machined from a single billet of steel, nickel plated for one of the most durable cassettes currently available. At 155g it is also one of the lightest The one piece design yields a stiffness increase of 15% over rivetted aluminium cassettes and the steel cogs are far more durable than titanium or aluminium. You may notice the missing teeth on the cassette, this is what SRAM calls OpenGlide it gives openings for the chain to shift quicker and crisper than previous cog designs.