Finally, a place where bigger really is better. What defines an efficient filter? As little pressure drop as possible. How do you achieve a low pressure drop? Surface area. How do you get a lot of area into a compact in-line filter? Pleats. More pleats means more surface area an, in turn, better-flowing filters. Aeromotive in-line filters boast the most surface area possible for the highest flowing filters. This product is not legal for sale or use on emission-controlled vehicles except when used as a direct replacement part matching OEM specifications.