Washable Aluminum Air Filter - 20 x 20 x 1, Duraflow Filtration, Mfr#: HDA3169

This heavy-duty washable aluminum air filter is permanent and washable. Built with premium aluminum, the frame features expanded and bonded aluminum filter media. The rear of the filter features a layer of expanded and corrugated aluminum to support the filter in high-CFM applications. This filter captures large dust particles and is useful upstream in your air intake to protect your HEPA or pleated filters downstream. Made in the USA, this filter will last for years and will never rust. Size:20 x 20 x 1. (Sizes are nominal, and 3/8" smaller than listed.)