Dimensions: 99mm OD x 61mm ID x 51mm high. Round; 98mm outside diameter x 73mm inside diameter x 51mm deep. Universal for many 4" round & 933807; 933808; 933854; 933853 Rough Crafts air cleaner kits. ''The Red Filter''. As used in Formula 1; Le Mans; Moto GP and World Superbike. Manufactured with a metallic mesh which contains multiple cotton layers of oiled filtration material. This allows improved air flow; sufficient for stock to all-out performance applications. To further help prevent small impurities enter the engine filtration oil is used to create a ''sticky'' barrier which allows air flow but helps retains small particles up to 7 micron. All filters are precision made and continuously checked during production for the highest obtainable quality. Filters are washable and reuseable. EU made.