Hot Tub Bubble Blanket - 6 x 6 FT 16-Mil Square Pool Spa Solar Cover | Heavy Duty Floating Heat Retaining Thermal Blanket for Insulating Solar Heating （Gray. 🛀【Wide Application】Inground Swimming Pool Solar Blanket is a practical and useful accessory for swimming pools, hot tubs, spas, ponds, etc.
eBay