this side-draft 37 x 37 x 42 cooler cover helps prolong the life of an evaporative cooler by preventing rust and corrosion to the cooler and cooler parts. the cover is 50% lighter than canvas and lab tested to be just as strong as traditional duck canvas. additionally, all seams are double stitched. the fabric is water resistant while still letting moisture inside the cooler escape. the cover and tie-down string are uv protected to prolong the life of the cover.