fridge filter certification change

Recently ordered new water filters from Frigidaire.com; the website pictures the filter tested and certified by NSF. I received the filter on the right.

Frigidaire customer service initially told me there is no difference and that I have to send the product back at my own expense before they’ll refund me. I have escalated my complaint, sent in photos and they are investigating the issue.

Any reputable sites that explain water filter certifications? Am I wrong to think a product that is “certified by IAPMO” is somehow inferior to a filter “tested and certified by NSF”?

Recently ordered new water filters from Frigidaire.com; the website pictures the filter tested and certified by NSF. I received the filter on the right.

Frigidaire customer service initially told me there is no difference and that I have to send the product back at my own expense before they’ll refund me. I have escalated my complaint, sent in photos and they are investigating the issue.

Any reputable sites that explain water filter certifications? Am I wrong to think a product that is “certified by IAPMO” is somehow inferior to a filter “tested and certified by NSF”?