... 'W x 15'L x 8'H, 4-Rib, 10'W x 20'L x 8'H, 5-Rib, 12'W x 20 ... 'L x 8'H 6-Rib, 13'W x 20 ... -Rib, - Super Heavy Duty Cover 14.5 oz.- 13'W x 24'L x 10'H 7-Rib, - Super Heavy Duty Cover ... 14.5 oz.- 13'W x 28'L x 10'H 8-Rib, - Super Heavy Duty Cover ... -Rib, -Super Heavy Duty Cover 14.5 oz.- 13'W x 36'L x 10'H 10-Rib, - Super Heavy Duty Cover ...