The Andersen Flaps 27" and 36" Eco-flaps splash guards are designed to be more aerodynamic. The wide, horizontal ribs have been removed to reduce wind resistance and improve fuel efficiency. The molded channels allow air and water to move through the flap surface with minimal drag to improve fuel economy up to 3.5 percent, according to the company. After moving through the channels, air and water flow reaches a dead-air zone on the back surface of the guard, where water falls to the ground, reducing road spray. Eco-flaps are made from durable, high-impact nylon to withstand extreme conditions. The 27" and 36" models have been added to the company's line of products that also includes 24" and 30" models.