Standard and Jumbo housings are manufactured of polypropylene. Leak proof sealing accomplished by cap impression against top seated 0 ring in sump. The square thread closure allows for years of cartridges change out without failure. These PP Molded Filter Housing are ideal substitute for costly low pressure stainless steel vessels. The larger body size allows for extra large cartridges & high flow rates. Polypropylene construction offers excellent chemical compatibility with Water, Beverages & Syrups and a broad range of chemicals.