4" Exhaust / Fresh Air 4" Port for Garage Door -Self Closing -for 2" Thick Doors
4" Garage Door Exhaust Port
A must have if you work on cars or other engines in an enclosed garage Overall diameter is 6".
Opening diameter is 4".
Can be used with up to a 2" thick door.
Self closing door will stay closed when not in use.
Made with black polyethylene (heavy pvc).