Cut to Size Premium Activated Carbon Filter Media.  Use for Air Vents, HVAC systems, Fans, and more.   

• 47″ x 15.75″, folded
• Great for emergency prepardeness for things like wildfires as well.
• Resistance: Gas Linear Velocity 1.0 m/s
• Estimated Pressure Drop ≤ 80 PA
• Carbon Media Thickness: 0.4″