Valve-in-Head filter housings incorporate the same rugged design and application features as the standard 3/4" NPT housings. The internal valve-in-head allows both inlet and outlet ports to be simultaneously shut off with a half turn of the handle, eliminating the need for external shut-off valves. Radial sealing O-rings and sealing surfaces are continuously cleaned each time the valve is used, ensuring leak-proof operation.  Housings are available in 10" and 20" lengths, and will accommodate a wide range of 2-3/8" to 2-7/8" diameter cartridges. The polypropylene caps feature a pressure-relief button on the inlet side to relieve pressure inside the housing when changing filter cartridges.  Opaque Valve-In-Head Filter Housings are molded from rugged reinforced polypropylene, offer outstanding chemical compatibility, and are ideal for use in a variety of low-flow applications. These applications include under-sink and countertop residential filtration, pre- and post-reverse osmosis filtration, recreational vehicle filtration, foodservice, and humidifying systems.