The air conditioner uses an air filter to help keep dirt, dust, and other airborne particles from getting into your home. The most common reason for air conditioners to not blow cold air is from being blocked or having dirty air filters. When the air filter becomes clogged or dirty, it will cause little to no airflow over the evaporator coils which will cause frost to build up due to the cold air and no circulation. This will prevent cool air from circulating into the room and the filter will need to be replaced. This air filter measures approximately 10” in diameter, is black in color, circle shaped, and it is suggested to keep the air filter clean to help maintain the productivity of the air conditioner. This air filter is a genuine OEM part.