Dedenbears Bear Stop Base Plate Throttle Stops Sit Underneath The Carburetor And Operate A Second Set Of Butterflies To Limit Air/Fuel Flow While Allowing The Carburetor To Remain In Wide Open Position In Order To Help Assist A Drag Car In An Electronics Class Precisely Dial In To A Pre-Determined Et (Such As Super Classes) Or To Aid In Running A Higher Mph For A Given Et. Typically Used With A Throttle Stop Timer, There Are Two Actuating Methods Available Offering Options For Improved Simplicity And Consistency Or Maximum Tunability. Electric Solenoid Stops Are Simple, Consistent, Reliable And Work For A Majority Of Applications. Co2 Or Air Stops Offer A Tunable Flow Rate, Allowing Greater Control Over The Stop Butterfly Open Rate (And In Dual-Acting Models Which Offer Control Over Close Rates As Well!), Reducing The Likelihood Of Spinning The Tires On A High Powered Car When You Transition Back Off The Stop During A Run.