Product review (3 stars): "Independently tested to fit NSF 42 and 53 standard (mechanical reduction)" is pretty misleading. I returned the item
Be careful, it is not a NSF certified standard 42 and 53 production. There is no NSF certified 42/53 statement on the box/filter.

"Independently tested to fit NSF 42 and 53 standard (mechanical reduction)" is pretty misleading.

I returned the item.