its an expensive little tool to simply get the throttle body to open more quickly, reducing lag...someone is going to try to duplicate it for a few bucks...but a tune will take it out as well...had I know the tune would have done it, I wouldn't have purchased the SB...we shall see what the knock off will do...but if you want to get rid of the lag, then tune, SB, or wait to see if the knock off will work...I haven't seen anything cheap yet, so this may be the first...we shall see....not going to get into another debate on this, the 300 buck part works for me...but it is 300 bucks, the tune is around 500 plus, so fingers crossed for the knock off...