Question:

Does the Pentek 155319, WS-10 Softening Resin Filter, #10 fit into a standard 10" housing filter?

Answer:

The Pentek WS-10 does fit in all standard Pentek Filter Housings and most other brand filter housings as well. I can not guarantee it will fit in every single brand filter housing, but it does fit the Pentek Standard Housings for sure.