Built to withstand the coldest winters, this energy efficient spa cover is perfect in heavy snow regions or anywhere a strong cover is needed. Using only the best marine grade Vinyl, this cover is 6″ thick at the center and 4″ thick at the edge. Aluminum C-Channel is installed into both foam inserts at the hinge. This cover has an R-35 rating. Both polystyrene foam inserts are heat sealed in a seven millimeter plastic. Double thick wrapping is available for an additional charge. Twelve different colors are available.