the D-box mounts inline with your steering servo and will help you counter the drift slide and not spin out when the back end gets lose. I think its a waste of money no need for some thing like this. the only thing its good for is some one who has never drifted b4. The better you get with drifting you will find the lower you will set the D-box and one day turn it off and not use it no more for you know how to drift and can drift better without it.
So unless you just cant pick up on how to drift good. I would spend the money on something eles. I dont think its worth the price you can go out to a big parking lot with nothing to hit and learn how to drift safe and not wreck your can.