Twin Air high quality air filter and fireproof, made with 3 different types of foam density, achieving greater air intake and maximum retention of dust and dirt. The best performance and maximum protection for your motorcycle engine. For the PowerFlow Kit for Honda CRF 250 R (2018-2019), CRF 250 RX (2019-2020), CRF 450 R (2017-2020), CRF 450 RX (2017-2020), CRF 450 RWE (2019-2020).