Originally Posted by Bill F

They are both selectable. The first sprint booster was non-selectable therefore, there, making the selectable #2 So go with the $299.00. I received mine through SRT SIX which I recall was less expensive. What I like is there are 3 settings, off, green for spirited driving or red for race. I keep it in the green and only use red when I'm at the Texas Motor Speedway.