The Pentek 154077 is the correct replacement filter cap for the following housings:
The Pentek 154077 Big Blue Housing 1" Filter Cap is a filter housing cap that fits Big Blue housings. This replacement filter cap features a 1" NPT inlet and outlet port and a 1.25" internal port that promotes the flow of a higher volume of liquid. In addition, the Pentek 154077 cap is manufactured with high-flow polypropylene for durability and longevity.
Pentek 154077 Big Blue Housing 1" Filter Cap specifications: