Up for sale or trade is a NIP K&N airfilter with lifetime warrenty card. I know it fits TRX motors, but it might fit many others. I think I read this model fits HPI 4.6 and others aswell. If you run Nitro then youd know more than I would. I recieved this a long time ago in a large parts lot. I only run electric so it will never get used. I checked these out on Ebay and there about $25 + shipping. I'll sell for $12 shipped.
Heres a pic. I also have a new HPI 18t clutchbell here that I could throw in for a few bucks.
http://i1116.photobucket.com/albums/...a/100_2654.jpg