The oil filter is an essential component for safe driving. Thats why each piece is carefully selected and carefully designed to achieve a high level of quality. ● Made of high quality filter paper. The filtration area has also been greatly improved compared to other products on the market. High performance filter paper keeps engine oil performing at its best. The check valve (diaphragm) uses high quality NBR rubber. Quality performance under all conditions and maintain proper flow rate The O" ring adopts genuine NBR. The material has excellent cold resistance, heat resistance, and sealability.