Our Electra-Kool filters are factory tested and approved. These rugged filters are made in the USA and feature metal endcaps and protective metal media covers. They are easy to install and have a rubber gasket that creates a tight seal against your housing. Metal Mesh filters are rated 60% @ AC Fine Dust and our Pleated Paper filters are rated for 99.9% efficiency @ 0.5 microns nominal. You can extend the life of your filter by utilizing a wraparound pre-filter. Our filters are in stock for fast shipping, so you can rest assured you will never be down for long when you trust in Electra-Kool.