The Twin Air Air Filter's design, high-quality materials and superior construction deliver unbeatable performance and protection - and make Twin Air Filters the hands-down choice of more World and National Champions than all other filters combined. Twin Air filters are designed to increase airflow while ensuring the highest level of protection from dirt / dust. Coarse 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 airbox, while acting as a breathable gasket for increased air passage.