Product review (2 stars): You get what you pay for...
Upon opening the package, I was unpleasantly surprised (disappointed) to find these filters were much lighter than the OEM Whirlpool filters I purchased in the past.  Thinking I would try a less-expensive generic brand, I realized I had likely made a mistake.  The weight difference was substantially due to less activated charcoal inside the filter, which is what makes a water filter effective.  This brand feels almost hollow.  You get what you pay for sometimes, and this is the case here.  I don't want to risk my family's health for a few bucks, so I'm returning this product and purchasing a brand name replacement.  I advise anyone else to do the same.