WHIRLPOOL WHEERM R.O. Membrane for WHER25 and Kenmore UltraFilter 450 R.O. Systems This is an original Whirlpool product. This Reverse Osmosis Membrane will fit the Whirlpool WHER25 R.O. System, along with the Kenmore UltraFilter 450 and the Kenmore Elite Premier R.O. System. This Whirlpool ( WHEERM ) membrane is used in the UltraEase R.O. systems, which utilize a very simple and easy to use "twist to remove / install" system. This product is Tested and Certified by NSF International against NSF/ANSI standard 58 in the model WHER25 and UltraFilter 450 for reduction claims specified on the performance data sheet included with the product.