Twin Air filters are designed to increase airflow while ensuring the highest level of protection from dirt/dust. Design, high quality materials and superior construction deliver unbeatable performance and protection. For Honda CRF 250 R (2004-2009), CRF 250 X (2004-2018), CRF 450 R (2003-2008), CRF 450 X (2005-2016), CRF 250 XRL, CRF 450 XRL (2015-2016).