Our Cross-Link polyethylene box is engineered to each specific application for low restriction and an increase in air volume. It insulates and protects the filter from engine heat, moisture, dust and debris to provide colder air to the engine for an increase in horsepower. Volant Air Duct: Factory air inlet ducts use sound baffles and awkward bends which restrict flow. Our Cross-Link polyethylene air ducts are sculptured to give the engine less restrictive breathing. Incorporating larger diameters and unique bends, that can’t be duplicated. With metal ducts, allow for maximum airflow velocity and throttle response.