Genuine Honeywell FC100A1037 HVAC Replacement Air Filter 20x25x4 Merv 11- 2 PACK
Exceeds Honeywell FC100A1037 specifications. Here’s how it worked. This pulled the stop from the motor gears, allowing a crank attached to the main motor shaft to turn one-half revolution. A chain connected to the crank opened the furnace’s air damper to let in air.