SRAM Red Rear Derailleur WiFli Medium Cage, 32 Tooth Largest Cog C2Top of the line rear derailleur with generous use of carbon fiber and titanium for maximum performance at minimal weight. Carbon fiber and aluminum construction Ceramic bearing pulleys Titanium hardware Graphics match SRAM Red eTap electronic components Item Specifications Color Black Weight 152 Largest Cog 32 Chain Wrap Capacity 37 Cage Length Medium keyword search RD4621 Drivetrain Speeds 11 Rear Der Shifter Compatibility SRAM Exact Actuation Rear