I was wondering how that filter adapts to the air box in 22RE Performance Mod tech article here on YotaTech. I'd like to try this, and i was just wondering how exactly it works? It looks like its just a foam thing squeezed over the boxs intake.

 

looks like he put a big cone or cylindrical filter on it with a maf adapter and a foam prefilter

 

Like Jim said above. No that is actually a round K&N filter with a foam sleeve around it for extra filtering (dusty situations etc..). It replaces the regular airbox by using a rectangle to round adapter attached to the AFM. Click here for an example of the parts I am not saying use that filter, but was just illustrate what you can't see in the mod write up pic.

Hope that helps,
Brad