Type 9 filter elements, for use in Hydac filter boxes, made of fiberglass (optionally water-absorbent), filter paper, wire mesh, and non-woven metallic fiber for various applications. They feature cleanable wire mesh media, achieve oil cleanliness class up to ISO 10/6/4 (ISO 4406), high dirt holding capacity, and filtration performance with low initial differential pressure. They are stable at high differential pressures, with nominal sizes from 60 to 660 and 30LA to 1500LA, differential pressure of 30 or 210 bar, and filtration classification from 1 µm. They replace Hydac D filter elements.