• 11 speeds / road bike • Compatible with RED eTap rear derailleurs and mechanical rear derailleurs (models 11-33D and 11-32D are not compatible with eTap drivetrains) • Graphics matching those of RED eTap components • Power Dome X design which produces the lightest and stiffest cassette on the market • 9 heat-treated middle gears machined from a single block of high-quality tool steel and a large aluminum gear • StealthRing elastomers between each sprocket to reduce noise and vibration • 151 g (11-28D)