Make: Marquis Spas; Model: 660; Year: Unknown; Replacement spa and hot tub covers by BeyondNice Feel confident - shipping is free. Don't worry about paying full retail. Buy directly from the manufacturer here, pay wholesale and save your time and money. Feel secure - we have made ASTM compliant replacement covers for 30 years and deliver via freight directly to your residence. Feel safe - our hot tub covers are backed with a 5 year warranty, including water logging and no need to return your cover. Spa covers can have sloping tops for rain run off or be flat for protected areas such as under a deck. This cover is 4 inches thick, tapering to 2. Thicker options are available and insulate better. Per the spa maker - Shape: Rounded Square; Size: 90 X 90; These are provided for reference only. BeyondNice can not verify their accuracy.