Right now there are 750 deals from Amazon Resale, formerly Amazon Warehouse Deals, in Industrial & Scientific › Filtration. These are inspected returns and open-box items that Amazon sells and ships itself. WarehouseHunter puts each one next to its current new price, so you can see what you save at a glance.

Brands with the most offers here: Nordic Pure, Filtrete, Aerostar, Pentek, Waterdrop, Westbrass, Crest, Aprilaire. Every item is a one-off, so the stock moves all day and new deals keep arriving.