• Frame is made from heavy, moisture-resistant chipboard in a one-piece design that eliminates corner separation.
• Filtering media is progressive density, continuous filament spun glass. A resinous bonding agent provides rigidity and resistance to compression. A viscous adhesive increases filtering effectiveness.
• These filters have been tested by Underwriters Laboratories Inc., and classified as Class 2 for flammability.
• Listed dimensions are nominal

Media support is provided on both sides of the filtering medium.