I have had problems with the plastic collar (on the wire cage inside) on my UNI air filters collapsing within a short time. http://forums.atvconnection.com/mess...y&keyword1=uni

As a solution, I finally spent the money for the Pro Design aluminum adapter, and that solves the whole problem. No way the metal is going to collapse like the wimpy plastic collar on the UNI's. The whole unit is very well thought out technically, and everything works very well together. The aluminum collar fits into the air boot, the wire cage fits over the collar (so the plastic can't collapse!), and the foam filter (it is a filter made by UNI by the way) fits over all of that. Excellent system that easily solves the problem! I just wish they made it for more models. (http://www.prodesignracing.com/)