A Caldera Spa hot tub cover is designed for maximum energy efficiency. Its tight seal insulates and locks in heat, saving you money on operating costs. Custom-fit to Caldera Spas, our covers are tapered for water runoff and are made from our durable WeatherPro material. All Caldera covers include child-resistant safety locks and incorporate the mounting plates necessary for attaching our hot tub cover lifter systems. Our covers also meet or exceed all ASTM safety standards for UL classification.