The Pentek 154291 is the correct replacement for the following housings:
The Pentek 154291 1" Cap for Big Clear Filter Housings is a replacement filter housing cap with a blue finish. This blue housing cap is compatible with Big Clear Housings and features a 1" inlet NPT/outlet connection. In addition, with the Big Clear housing cap you'll see the benefits of its durable polypropylene construction, which makes it stronger and longer lasting.
Pentek 154291 1" Cap for Big Clear Filter Housings specifications: