These Air Filters have a precision woven 304# stainless steel outer construction. With triple layer protection, they increase air flow over stock filters. The filters are corrosion resistant, environmentally friendly, and are washable and reusable. Having over 100 applications, 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 check out all of our filters and applications.