Lay-Z-SpaTHERMAL HOT TUB COVER: Keep the heat in, save energy and make your hot tub up to 40 percent more energy efficient with the Lay Z Spa Thermal Hot Tub Cover. The must have insulating accessory to reduce your hot tub running costs and keep enjoying your Lay Z Spa all year round IMPROVE INSULATION: This insulating hot tub cover offers a double layer of cotton thermal insulation, making your inflatable hot tub up to 40 percent more energy efficient. The