Insulated Fan Cover, 21-1/2 In O D

Insulated Fan Cover, Depth (In.) 3-1/8, Outside Dia. (In.) 21-1/2, Polyethylene Construction Material, Includes Magnets, Drawstring and Hook and Loop Closure, Stops Unwanted Infiltration Weather, For Use With 16 Inch Shutter Mount and Guard Mount Exhaust Fans 1HLA3, 1HKL5