Outerwears Air Flow Replacement Pre-Filter 20-1800-01Dyno and flow bench testing has shown no significant loss of horse power or air intake while using this product Silicone impregnated micro mesh is water resistant Seams are dielectrically welded Material contains uniform micronsized openings that allow air in, yet filters out the unwanted elements, such as sand, dirt, clay and even water Filters particles as small as . 005in. in diameter without noticeable air flow restriction