The Whirlpool UltraEase Reverse Osmosis Membrane WHEERM (WHEERM5) is the replacement membrane for the WHER25 Reverse Osmosis System. It is a thin film composite (TFC) membrane.
WHEERM has been certified and tested against NSF/ANSI standard 58 for the reduction of total dissolved solids and organic matter and has a rejection rate of 90-95%.
WHEERM typically lasts a year, depending on your water's pH level and hardness. The membrane, also known as 129801 & 7296123 should be replaced after a decrease in water pressure or quality. Also replaces Kenmore 42-38577.