The Big Blue size 20" Filter Housing with pressure relief is an extra-wide housing that accommodates large 4.5" wide filters for increased flow. It is made of a durable, reinforced polypropylene that is usable with a variety of noncorrosive chemicals. The housing cap is a high-flow polypropylene cap with 1" external female NPT ports and large internal ports, allowing water to pass through rapidly. This 'Big Blue' size filters is an excellent choice for whole house or commercial applications where high flow rates are required. 

Please Note: This is the housing assembly only and DOES NOT include filter cartridges (# CB-45-2005) or brackets / mounting screws (# FM-25W), sold separately.