The 300d x 300d polyester fabric with double stitched seams, strong draw rope and heavy-duty brass grommets. Compared to canvas, these covers are stronger, last longer and wont shrink. The water-resistant Polyurethane coating prevents water from entering cooler while still allowing water vapor to escape, inhibiting moisture buildup inside cooler. Cover is suitable to all seasons as it protects cooler from rain, snow and UV.