Pro Oil Filter Cover. RFX Pro Series Oil Filter Covers are manufactured from 7075-T6 aluminum for increased dimensional stability under high heat and pressure conditions. RFX Filter Covers also feature an increased flow design for better oil circulation. RFX products are tested and used by many top Grand Prix and British Motocross teams. Features: 7075-T6 aluminum construction. Increased flow rate design. Color anodized. Lightweight hollow design. Accepts O.E.M. O-rings.