This kit was very impressible, its basically just like the Twin Air Power Flow kit but has a plastic cage instead of the aluminum cage of the Twin Air kit. I wish I had a Standard No Toil or Twin Air filter to run with the backfire screen still installed in the stock cage so I could compare that to the stock filter and then the Super Flow kit. Bottom line, going from the stock filter and cage with the backfire screen still installed to this No Toil Super Flow kit absolutely made a very noticeable difference in low end torque and top end over rev IMO. I'm sure the Twin Air kit is just as good and it comes with the nice aluminium filter cage but the $150 price tag of that vs the $50 price tag of the no toil is what makes this kit so nice. Also the replacement filters are much cheaper in cost, the foam quality seems just as good as the Twin Air filters to me. For a little under a $100 you can get the Super Flow kit and 2 extra filters and I think it made as much of a difference or more as the $1400 exhaust system. I'm not sure if the kit would work as well with stock exhaust but with the Yosh full system already installed, I was extremely impressed with the gains of a $50 product. All that is done to the bike is the full Yosh Ti exhaust system and the Super Flow kit, still has stock programming and I think it runs very well with this setup. No Toil!!!! I am in no way affiliated with No Toil, its just not very often I am overly impressed with a product.