SYSTEM:2 MODULAR D.E. FILTER PLDE SERIES - Sta-Rite delivers the unique benefits of D.E. filtration in a variation of their proven modular media technology. A single replaceable grid delivers water of superior quality without the complex workings of other D.E. filters. This innovative one-piece design is fully backwashable and can be plumbed with or without a backwash valve. 2" union valves are included for installations electing not to use a backwash valve. For deep-down cleaning, simply remove the filter lid and hose off in place. No more hassle of tearing down the grid assembly for cleaning and servicing. CERTIFICATION - The filter shall be tested and certified by a nationally recognized testing laboratory to conform to NSF Std.50.