These Air Filters have a precision woven 304# stainless steel outer construction. With triple layer protection, they increase air flow over stock filters. They are corrosion resistant, environmentally friendly, and are washable and reusable. The BikeMaster Air Filters are a quality aftermarket product that goes above and beyond the OEM while maintaining a reasonable price. Please go to our website, www.bikemaster.com, to view all of our pod filters as well as our OEM replacement filters.