Product review (1 stars): Not NSF/ ANSI 53
These are not NSF/53 certified, which is why they cost less than the brand name filters.  GE is the only company on the NSF web site that has an NSF 53 certification for MWF filters.  GE and Ecopure are the only companies listed for NSF 42, which is only for odor and taste.  A link to NSF is below:

http://info.nsf.org/Certified/dwtu/