Twin Air Filters design, high quality materials and superior construction deliver unbeatable performance and protection and make Twin Air Filters the handsdown choice of more World National Champions than all other filters combined. Coarse openpore foam catches airborne dirt, grime and sand. Fine openpore 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 airbox, while acting as a breathable gasket for increased air passage. Fused outer and inner elements prevent dirt and grime from being lodged between layers, unlike Twin Air, this can be a problem with inferior twopiece designs. Trapped particles can restrict airflow. And if dirt works its way into your engine, a pinheadsized granule will gouge your cylinder, piston and rings like a bullet. Used PreOiled Air Filter. The coarse