1. K&N - Old #MG-1093, New # 33-2682 (Automotive application that fits perfectly)
2. BMC #F45740 AND Airbox lid eliminator kit for newer Guzzi's - Sold by Fast by Ferracci
3. *Discontinued* Amsoil Products 2 stage foam # S1938 - grab one while they last. See Amsoil link from main page.
Seperate Filters for those eliminating the airbox:
1. Tapered: RU-2580 (these are kinda small)
2. Non tapered: RU-0500 (smaller than below, but still good)
3. Non tapered: RU-0510
4. Non tapered: RU-0520 - Mostly the same dimensions as RU-0510, but 25mm/1" longer.
*5. Non tapered: RU-0600 - 4" l. x 3.5" dia. - 2.25" flange
1. UP-4200 Foam Pod (2" I.D. x 4" L)
*Note from Jason Tucker - I think this filter provides the most surface area, given the space the filter must fit in.
Please note that you shouldn't try to mount the filter directly on the throttle body. The filter I specified should be mounted on the intakes (that connect the throttle body to the airbox). You have to remove the intakes from the airbox, and then cut off the flared end. Try to keep these intakes as long as possible... only trim off as much as you have to to get the filter to fit. Due to the offset of the cylinders, the right intake may be a bit longer than the left - this is OK. I also used a pipe cutter to score some grooves in the end of the intakes - this helps keep the filters in place by giving them some "tooth" to hold onto.