GeneralAire ReservePro Merv 11 Replacement Expandable Filter Media
Micro Fiber MERV 11
Media for GeneralAire Model # AC4
Installation Instructions are located on the box.
The air filter media can last up to 6 months. It may be necessary to change the media more frequently, in the presence of a high concentration of dust and/or particulates, or if the furnace fan is running continuously. In any application, the life of the media depends on the total volume of air being moved through it and the amount of particulate it is filtering. Inspect your air filter every month for cleanliness.