The ALSF4’s surface-to-volume ratio and interior design work together to provide highly efficient filtration. The large screen surface, relative to liquid flow, reduces obstruction by preventing contaminants in the liquid stream from collecting in one area. The ALSF4’s interior is designed to move liquid through the filter body in a swirling motion that distributes contaminants evenly over the filter cartridge and moves any solids toward the base of the bowl.