Remember when your workshop was full of clean air? Air-borne dust particulates can dirty up a woodworker s shop and harm a healthy respiratory system. It s time to keep your lungs happy with the WEN 5-Micron Industrial-Strength Outer Air Filters. These filters have been specially designed to fit the WEN Three-Speed Remote-Controlled Industrial-Strength Air Filtration System, 556 702 1044 CFM (model 3415, 3415T, and 3417). However, their universal build can also fit in the majority of 1044 CFM air filtration systems on the market. With simple tool-free installation, you ll be able to quickly replace your existing filters. Sold in packs of two filters.