Permaire is a unique completely synthetic, self-supporting and washable media. Permaire media cut to the proper dimensions is actually a complete filter ready to install. With nothing more than Permaire and a hefty pair of scissors or a razor knife, replace almost any size 1/2", 1" or 2" framed panel filter. Permaire filters are passive electrostatic type products. Air running over the maze of fibers creates an electrostatic charge to catch and hold airborne contaminants. Dirt loads throughout the filter's depth holding a lot more dust than other filters before requiring changing or cleaning.