WHKF-GAC Compatible Carbon Filter, KleenWater Granular Activated Carbon Replacement Cartridges, 2.5 x 9.75 inch, Qty 3 Three KleenWater 2.5 x 9.75 inch granular activated carbon water filters The cartridges are high quality low cost alternatives to Whirlpool WHKF-GAC The universal dimension of 2.5 x 10 inch is compatible with Culligan, Cuno, Ametek and most others. Free USPS Priority Mail shipping. Ideal for "point of use" or under sink filtration Replace cartridge every 3-6 months or upon substantial pressure reduction