Made of microporous filter paper treated with resin, it has the advantages of high filtration efficiency, light weight, and low cost, and is widely used in automobile engines. Made of sponge-like polyurethane material, it has strong adsorption capacity but low mechanical strength, mostly used for car engines. Through three-stage filtration (inertia, oil bath, filtration), the intake resistance is small and the life is long, but the maintenance is complex and has gradually been phased out. Specifications: Various car engine specifications.
