K&N 66-1601 K&N X-Stream Top Filter X-Stream 16in OD - BlackK&N 66 1601 K&N X Stream Top Filter X Stream 16in OD Black K&N XStream Air Flow Tops replace the top of your existing round filter and add a new dimension to engine breathing by feeding your engine all the air it can use. They are washable and reusable just like other K&N Air Filters. Air filter top adds filter area Replaces metal factory filter lid with a lid with a built in air filter top High air flow with excellent filtration Washable and reusable