The Jacuzzi hard covers are manufactured from 70mm Styrene and claded with either Vinyl or PVC Canvas. Vinyl is suited for in-door use. PVC Canvas is more hardier and is better suited for out-door use than Vinyl. The Styrene is covered with plastic, preventing it becoming waterlogged. The bottom is also covered with Vinyl or PVC Canvas preventing the chemicals attacking the styrene. The most heat loss occur due to radiation from the top of the spa and the cover is a cost saver, also keeping dust out of the spa.
NOTE: The cover is not a safety feature and will break if a child or animal climbs on it.