This part is the replacement air filter for your room air conditioner. It is framed by white plastic and is approximately 18 inches wide and 8.5 inches long. The air filter protects your home from airborne dirt, dust, and other particles. If the air filter is damaged, it can allow these particles to pass through, and become distributed around your home. A damaged air filter will need to be replaced. This part is sold individually and is an OEM part sourced directly from the manufacturer.