Product review (3 stars): Not NSF/ANSI 53 Certified
I have not bought this but my water supply requires impurities to be cleared.  I would prefer NSF/ANSI 53 certified and this product is NOT.  Despite what the product description said here is the response I got from Sentinal (the manufacturer):

"We are certified to NSF standard 42 which concerns taste and odor. Standard 53 deals with specific contaminants that are removed from the water. We are not certified to NSF standard 53, however, we have designed this filter to perform the same as the OEM filter it replaces.  The filter is engineered and built here in California at our factory.  It is made in the USA.  The filtration technology used inside the filter is the same as has been used in most refrigerator filters made and sold over the last ten plus years.  We have had direct experience in manufacturing drinking water filters here in the USA for over 20 years.
Because we are not the manufacturer of the refrigerator we are not able to make specific health claims for the product.  Therefore we cannot make specific claims related to the contaminants that are removed.

We do offer a simple 90 day money back guarantee if you are dissatisfied with the filter for any reason."

Please factor this into your purchasing decision - Amazon's description is NOT accurate.