The Turbo II line of intake precleaners are very popular - and for good reason. They are made of heavy-duty steel, are very efficient, are easy to install, they have a lifetime warranty on the spinner, and they even look pretty. This one fits on either a 4" or 4.5" inlet tube (4" adapter must be purchased separately).
Recommended C.F.M Operating Range 350 to 700
Precleaner selection must be based on engine air
flow specifications - NOT on inlet tube diameter.