Twin Airs Monofilament screen pocket, inserts into the fuel filler to catch particles as small as 40 microns (0.00165") while allowing fuel to flow freely.  The flange is individually designed for each modern 4 stroke model to ensure a leakproof seal.  Just remove the filter periodcally, turn it inside out and clean out the derbris that could have been in your engine.

You'll be amazed at the amount of dirt and debris that gets into your fuel bottle, and from there, into the fuel tank.