Durable and high-quality round insulated covers for round hot tubs with external heaters. A cover is especially useful accessory, with it you can speed up heating of your hot tub, keep the water hot for a longer time and optimize heating performance on the following day. The cover also protects your hot tub from debris and with a cover your hot tub remains clean when empty, and as well it protects inner parts of hot tub from UV-radiation. The cover improves safety especially for families with children and pets. The cover has been standardized (EN 17125) as a safety cover.