Francis Fuels Ltd

GeneralAire MAC1200 Replacement Filter Media # GF4521


MERV 8, Replacement Filter Media # GF4521

Featuring Opti-Fiber Media.

• A highly efficient depth loading filter media that captures particulates deep within the layers of media fibres.
• Opti-Fiber Media delivers an effective Minimum Efficiency Reporting Value (MERV) that performs to remove airborne particulates efficiently down to 1.0 micron.
• The Spun bonded fibres are free of chemical binders and considered hydrophobic - they do not absorb moisture.
•The Opti-Fiber high initial efficiency media resists shredding to assure dependable dust fighting capabilities.


  • MERV 8
  • Opti-fibre Media
  • 16x25x3 nominal approximate size
  • 15 7/8" x 24 1/4" x 3"

Fits the:

GeneralAire MAC1200,  # 4521

TRION AirBear Cub 1200. Replaces TRION media part # 255649-101  


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 is dependant upon the total volume of air being moved through it as well as the amount of particulate it is filtering. Inspect your air filter every month for cleanliness.