WHKF-GD05 Whirlpool, 3M Aqua-Pure AP110 Compatible Filter, KleenWater KW110 Grooved 5 Micron Water Filter Cartridges Set of 6, O-ring for WHKF-DWHV, WHKF-DWH, WHKF-DUF Qty1 These 6 cartridges are high quality low cost alternatives to Whirlpool WHKF-GD05 3M Aqua-Pure 110 5 micron dirt removal rating with raised grooved for longer service life 8 gallon per minute flow rate Replace cartridge every 3-6 months or upon substantial pressure reduction The o-ring is made of Buna nitrile rubber which creates a positive, dependable seal