Twin Air Filter Hon Alp 150602Standard Air FilterCoarse open pore foam catches airborne dirt, grime and sand Fine open pore inner foam acts as a second filter to trap the smallest particles while ensuring maximum air passage Exclusively formulated adhesive ensures glue seams will not break down Thick flat foam greaseless sealing ring ensures maximum contact with your air box, while acting as a breathable gasket for increased air passage Fused outer and inner elements prevent dirt