(Six) KleenWater KWWH25RG Water Filter Housing Replacement O-rings for Whirlpool Filter. We recommend consumers keep a spare o ring on hand to avoid urgent situations. This o-ring is compatible with Whirlpool filter housings: WHKF-DWH, WHCF-DWHV, WHCF-DWH, WHKF-DWHV & WHKF-DUF. An o ring facilitates a water tight seal between the water filter sump and the water filter head. The most common o rings used in water filtration are made from Buna-N material. Buna N is also commonly referred to as nitrile. This is the ideal choice for cold water filtration because they are inexpensive and have superior performance characteristics. KleenWater is a trademark of Pavel Water Filtration.