Arrow - 20" Big Blue Double O-Ring Filter Housing Black Cap / Blue Sump with Pressure RelaseArrow Big Blue Filter Housing 20" Big Blue Double O Ring Filter Housing Black Cap Blue Sump with Pressure Release 100 PSI Max Pressure 1" NPT Connections Pressure Release Button Four Mounting Bosses The Arrow 20 inch Big Blue Filter Housing delivers high flow whole house filtration for residential, commercial, and industrial applications. Built with double o ring seals and a pressure release button, this housing handles flow rates and pressures that