High performance replacement air filter handmade in England. Materials are identical to those used in Formula 1 and WRC. The TriFoam concept with 3 layers of high filtering power foam blocks dust particles down to 5 microns. Allows more air to pass through than most cotton or paper air filters on the market. Saves fuel at the same speed, more power by reducing pressure drop, cleanable and reusable. Service life up to 10 years. To be oiled before use.