Speed Dealer Polished Aluminum Domed Choke Knob for S&S Super E G Carb Billet aluminum choke knob that matches our velocity stack. Machined from solid T6061 aluminum and polished to a mirror finish. Mounts with a set screw on your stock choke rod - new set screw provided This knob has three settings: Off - Half Choke - Full Choke Half choke is perfect for warming up without running your bike at high RPM.