Product Review

Two Water Filter Housing Replacement O Rings compatible with 3M Purification Aqua-Pure AP801 / AP802. For (3) AP810 compatible cartridge kit with (1) o ring Amazon Search KW810EC(3)-AP801oring(1). This convenient cartridge - o ring kit is $68.00 with free shipping. We recommend consumers keep a spare o ring on hand to avoid urgent situations. This o ring will accommodate filter housings which require large diameter cartridges. These cartridges have an approximate diameter of 4.5 inches. The o ring itself actually measures approximately 5 5/8 inch (inside diameter). An o ring facilitates a water tight seal between the water filter sump and the water filter head. The most common o rings (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.