Hot Tubs Heat Preservation Foam Mat will protect your hot tub from rough surfaces and ground debris. It will also preserve heat in your spa and prevent the bottom of your spa from getting cold in winter. Spa heat preservation foam mats are suitable for most hot tubs (Round/Square) and are supplied in 9 pieces per pack. Shatchi Hot Tub Spa Heat Preservation Foam Mat (9pcs Pack) in Silver Size: 6 Person