Filter housings are used to contain filter cartridges for use in many water purification applications. In home applications filter housings are often used for sediment cartridges, and for activated carbon (charcoal) filtration. Filter housings come in a variety of shapes and sizes. They differ in length, width, inlet/outlet plumbing, and color. Some filter housings include a pressure relief valve and/or a mounting bracket. aQuatell carries a full line of water filter housings including 10", 20" and big blue style products.