Product review (3 stars): NSF confusion explained.
This is my 2nd purchase of this product.  The first purchase in Nov 2015, the second in Dec 2016.  I will cut to the chase....these work well, do not leak and I have had no issues with them at all.  So why the 3* review?

1.  The ones purchased in 2015 had both NSF 42 & 53 certification on the box.
2.  The ones purchased in 2016 ONLY had the NSF 42 certification.

This explains why there is conflicting information on this particular filter in the reviews.  Sometime between 11/2015 and 12/2016 they changed the product, changed the box, or the product is the same but failed subsequent NSF 53 certification by an independent agency.  Bottom line, if you value NSF 53 certification as I do, these will no longer meet your needs.