Profile: CleanAir Systems, Inc. designs and produces emission control systems for on and off road vehicles, machinery & stationary generators. Our Permit™ filters are designed to control particulate matter (PM), carbon monoxide (CO) and hydrocarbons (HC) from any size diesel engine. Utilizing a wall-flow ceramic filter coated with unique catalyst, the catalyzed particulate filter dramatically reduces black smoke and odor associated with diesel exhaust. The Permit™ filter is packaged in a 304L stainless steel shell, finished by bead blasting, offering a highly corrosion-resistant product.