Product review (5 stars): The Best Filter on the Market
These are the real deal not some cheap knock-off. This filter meets NSF/ANSI Standards 42 and 53.  Many of the filters you see on Amazon and elsewhere only meet Standard 42. There is a huge difference between the two standards.
NSF/ANSI Standard 42:
The commonly tested chemical reduction claims for products seeking certification to NSF/ANSI Standard 42 are: chlorine (taste and odor), chloramines, iron, manganese, hydrogen sulfide, pH neutralization and zinc reduction.

NSF/ANSI Standard 53:
The commonly tested chemical reduction claims for products seeking certification to NSF/ANSI Standard 53 are: heavy metals (arsenic, cadmium, chromium, copper, lead, mercury and selenium), inorganics (fluoride and nitrate plus nitrite) and volatile organic chemicals (chloroform surrogate as well as individual organic chemicals).

Also many unscrupulous vendors will claim that the filters meet both 42 and 53, then ship the unknowing consumer a filter that only meets standard 42.  This is not the case here.  These are the real deal. If you should decide to buy another type of filter, please check the package when it arrives and make sure it clearly states they are NSF/ANSI Standard 42 and 53 approved