4395608 vs. 4396510 - What's the difference?

Topic: Differences between the "Deluxe and Ultimate" Refrigerator Filters for Whirlpool, Sears/Kenmore, Thermador, KitchenAid Refrigerators:

We get lots of questions about the differences between these two filters - this article was created to answer these questions. 

Whirlpool Deluxe Refrigerator Filter (4396508, NL240V)

Whirlpool Ultimate Refrigerator Filter (4396510, NLC240V)

Physically, the filters are identical and are interchangeable in the filter receiver on your fridge.  The 4396510 (Ultimate) filter is a "better" filter - in that it is rated to remove more contaminants from your water - most notably cysts.

The 4396508 (Deluxe) fridge filter has been tested and certified to remove the following from your water:
Chlorine - 99%
Lead - pH 6.5 - 99.35%
Lead - pH 8.5 - 99.31%
Mercury - pH 6.5 - 96.22%
Mercury - pH 8.5 - 91.57%
Benzene - 96.4%
p-Dichlorobenzene - 99.77%
Toxaphene - 92.86%

The 4396510 (Ultimate) fridge filter has been tested to remove the contaminants above PLUS:

Cysts 99.99%
2,4-D 93.06%
Atrazine 85.06%
Asbestos 99.93%
Turbidity - 99.3%

Another difference between amount of water they will filter between changes.  The Deluxe Refrigerator Filter (4396508, NL240V) is rated for 500 gallons, while the Ultimate Refrigerator Filter (4396510, NLC240V) is rated for 400 gallons.

Bottom Line - the 4396508 filter and it's equivalents can be used in refrigerators that call for the 4396510 - they will fit.  However, if you are concerned about additional contaminants in your water - such as cysts (and you want the best filter money can buy) - it's probably best that you stick with the OEM filter.