The Hunter FE09 Oil Filter Envelope 17-1/2" x 18-1/2" CS100 is designed to help maintain efficient oil filtration by capturing contaminants and supporting cleaner oil circulation in compatible filtration systems. Made to fit securely within the filter housing, this filter envelope allows oil to pass through while trapping dirt, sludge, and other particles that can affect system perfor... https://partsfe.ca/fe09-hunter-filter-oil-envelope-17-12x18-12-cs100