Envirogard’s BH filter housings are designed for higher water flow applications, up to 40 US GPM. They are made from 100% food grade PP, and feature a unique double-“O” ring seal that prevents leakage even under stressful and variable conditions. Pressure relief valves are standard on all models. Filter Wrench is included and mounting bracket and mounting screws are optional. Filter cartridge not included. Tested & certified by CSA to CSA B483.1 & NSF/ANSI 61.