GSW 18” White Powder Coated 4-Way Adjustable Metal Diffuser for Evaporative/Swamp Cooler, 20” Mounting Edge (18"x18"x6")

Concern: closing four side vents for winter leaves gap at top where air can still flow through metal diffuser. Solution: purchase a 2'x2'1" Owens Corning Foamular (stiff) insulation sheet at Home Depot, for example, and cut it to fit inside diffuser (in my case, 20"x20"x1"). You need to leave vents open, however, for insulation to fit snuggly inside. With insulation air can't flow through diffuser even though vents remain open. I put a hinge on one side of diffuser rim so as to more easily insert and remove the insulation with changing seasons.

After an hour and a half of Time working I got all of the lovers to work.....this item is wonderful when you spend the time fixing it....you can send it back 100 times you WILL never get one that works .... YOU must message the hinge area of all the vents each end and then it is really good.....There are 40 single hinges ....so take you time

Very well built and good finish

Excellent construction and easy installation.

It is ok, but the corners that mount on the dry wall are not finished well and they are bent up slightly. I think can fix this (get them close to straight before installing and then caulking when in place) but I'm not impressed with the way it was shipped.Why not put a 1/4" or 1/2" piece of plywood on it, to keep the corners straight? I nearly returned it but reluctantly decided it was easier to try and make it work.Other than that the construction is good and the finish is good, except at the corners.