Pentek 3G Standard Filter Housings are made of durable polypropylene and features 3/4 inlet and outlet ports. Polypropylene housings offer excellent chemical resistance and accommodate a wide range of 2-1/4 to 3-1/8 diameter cartridges making them ideal for residential commercial and industrial applications. Features: Ideal for a wide range of applications including residential commercial and industrial Buttress threads for additional strength and easier cartridge changes Thick walls for increased strength Leak-proof sealing with top-seated 151120 Buna-N O-ring Excellent chemical resistance Integrated Mounting Bracket with Pressure Relief Button Filter cartridge sold separately