This is a Pentair Purex SM-SMBW 20448/4048 Filter Grid Element 48 Square Feet. This filter element is for SM-SMBW 2000/4000 Series D.E. Filters.
These grids are injection molded from 100% virgin, high impact styrene then covered with multi-filament polypropylene fabric. Each grid has been engineered with subtle design improvements specifically for this model and manufacturer.
