7100293 - 20" Full Flow Blue Housing And Black Cap With 1 In Port And Pressure Relief ValveWatts 7100293 20" Full Flow Blue Housing And Black Cap With 1 In Port And Pressure Relief Valve This 20 inch blue housing with a black cap accepts Full Flow filters. The housing cap features a 1 inch NPT pipe size connection with a pressure relief valve. A leak proof sealing is accomplished by compression against a top seated EPDM O ring located in the housing's sump. The heavy duty construction is made using high quality FDA grade polypropylene. It