The Polini air Filter has two layers. The first layer has medium sized pores to filter rough dust particles, approx 30 pores per inch. The second layer has very small pores that can also filter dust particles of microscopically small size – approx 60 pores per inch. It is these dust particles that cause major damage to the motor. The filters are made of self extinguishing polyurethane foam. Their two layers are joined together by means of a special hot forming process which does not manipulate the filtering properties.
The rippled outer surface of this performance air filter element facilitates an increased flow of air, with at least 50% more air being filtered than with more common types.