LIQUATEC FH04 SERIES COMMERCIAL FILTER HOUSINGS are manufactured of reinforced polypropylene. Most 20 x 4.5" cartridges fit easily. Our commercial grade products have excellent chemical resistance and are ideal for many residential plumbing, commercial and light industrial applications. Our superior technology along with our quality control measures in place allow for a cost effective solution for many of your filtration needs. As an economical product this will allow your customers to maximize their profits with out jeopardizing quality.LIQUATEC FH04 SERIES COMMERCIAL FILTER HOUSINGS are Tested and Certified by NSF International to NSF/ANSI Standard 42 for material and structural integrity requirements only.Specification HOUSING POLYPROPYLENE CAP POLYPROPYLENE BUTTON ASSEMBLY STAINLESS STEEL, EPDM AND POLYPROPYLENE Pressure Release Yes O-RING BUNA-N MAXIMUM TEMPERATURE 125°F (51.7°C) MAXIMUM PRESSURE 125 PSI (8.62 BAR)