Product review (4 stars): A Breath Of Fresh Air For Your Refrigerator.....With Some Caveats To Consumers!
If you have recently purchased a new frig as we have, you will no doubt appreciate many of the new "bells and whistles" engineered into today's sophisticated appliances.  To me however, this snap-in activated charcoal air filter is something that should have been designed into these units decades ago. It essentially eliminates the need for auxiliary boxes of baking soda in order to address and neutralize offensive odors from food.

Here's what you need to know to be a consumer-savvy smart shopper:

PROS:

1. Genuine OEM air filter compatible with many Whirpool, Maytag, Amana and Jenn-Air refrigerators. (Check your owner's manual to insure
  you are purchasing the correct part number for these filters.
2. Extremely easy snap-in installation.
3. Filter media impregnated with activated carbon (charcoal).
4. Designed to be replaced at 6 month intervals per your appliance manufacturer.
5. Supplied with a separate triangular plastic replacement indicator  ("Time Strip") as a visual reminder when to replace. (See Photos).

CONCERNS:

1. Cost: Pricey when you factor in the long-term costs of replacement. Depending on your particular model, many refrigerators are designed
  with multiple "peripherals", requiring replacement at given time intervals-water filters, multiple air filters, etc.  If you have a unit with many
  "bells and whistles", be prepared to shell out hundreds of dollars over the life of the unit for these "accessories".  Think of it like getting
  a subsidized computer printer for a great price initially, and then getting screwed on the price of the printer cartridges-sound familiar??

2. These filters are not manufactured by Whirpool Corporation but FOR Whirpool, USA by Kemflo International (Taiwan).
  My educated guess is that they cost about 0.35 cents each to produce-you can do the math to quickly determine how much profit is generated
  on the sale of these filters, even at the "discounted" price of $7 per filter.  Here's an interesting  link to a major supplier of Kemflo filters:
 http://www.alibaba.com/product-detail/Whirlpool-W10311524-AIR1-Refrigerator-Air-Filter_60345399930/showimage.html

3. Triangular "Time Strip" indicator not installation-compatible with many refrigerator models, requiring consumers to "retro-fit" installation.
  I simply inserted the strip into a crevice on the top of my refrigerator ceiling. They are easy to lose without a secure installation.

RECOMMENDATIONS:

1. A necessary and convenient maintenance item for virtually every refrigerator.  Highly recommended.
  Purchase in volume rather than for one filter.  Shop wisely-there are many vendors online offering these exact filters at less than half the
  MSRP compared to ordering these filters directly from Whirpool.  You should be able to purchase a set of three of these filters for about
  $20.

2. Periodically check the filter(s) at 3 month intervals. You may find that you can go 6-9 months or longer depending upon the length of time
  and frequency that your compressor runs. If your filter begins to develop mold, wash or replace the filter immediately.

3. BEFORE you purchase any appliance, factor-in the annual cost of all of these "maintenance accessories". Very few of us do including myself.

To Your Good Health!