its just a canister... they are worthless. they give you a little low end if you let it idle for a few seconds before romping on the throttle, once you get moving past 3 mph, they start robbing you of power since they add extra volume to your block. to run one of these you tap a nipple somewhere in your block. i knew a dude that had a spree, he got one designed for a spree and we put that on... you can deff. tell the difference, but you dont go any faster, from what we could tell it made it run smoother, but that may have been a pacebo effect.