Fiberglass wound on 316 Stainless steel core to filter oil from 100 micron down to 50, 25 10, 5 or 3 micron particle removal. Dirt holding capacity ranges from 0.2 to 0.75 lbs/10 in. length of element with better than 95% efficiency.
Elements are also available in cotton and polyester materials for other oils and fluids.