Product review (4 stars): Aquafresh
These worked fine for a replacement of the OEM. Couldn't tell a difference in the taste or color etc.  Need to run some water through them as it will start out a little grey/cloudy and then clear right up.  No issues with fitting into the attachment, although the end isn't supported like the OEM version.  No big deal as the compartment lid snaps in place and holds the unit.  For the money I can't see why anyone would want to pay more for the original brand.