Domnick Hunter HIGH FLOW BIO-X filter, 2.5 inFiltration Media: PTFE ImpregnatedBorosilicate MicrofibreUpstream Support: PolypropyleneDownstream Support: PolypropyleneInner Support Core: 316L Stainless SteelOuter Protection Cage: PolypropyleneEnd Caps: PolypropyleneEnd Cap Insert: PolyethersulphoneStandard o-rings/gaskets: SiliconePrice per 3-pack