Water Sparks filter housing is Big Blue Filter, Standard and filter housings are manufactured with reinforced polypropylene or clear Styrene-Acrylonitrile. The filter housing offers an optional pressure relief button.Water sparks Filter Housings are an excellent choice for when space and chemical compatibility are primary concerns. low-flow applications and. Reverse osmosis water purification process uses this filter housings. Water sparks Big Blue Filter Housings offer large-capacity filtration, ideal for high flow and heavy sediment applications. RO membrane housing and RO Filter housings are Filter Housings are designed to fit standard 5-inch, 10-inch and 20-inch filter cartridges. Pressure relief button on the inlet side to relieve pressure inside the housing when changing filter cartridges.