I purchased this for two reasons. One, to keep the shape of the outer cover suitably supported and two, to see how thermally efficient this cover is. I can happily say that this cover works great on both fronts. Temperature hardly falls at all if tub has to be switched off overnight. All in all, an excellent purchase.

Helps keep heat in and prevents lid sinking in rain brilliant.

Not much info how to use, should it sit on the top of the water or above it? Not touching? Seems To be working difficult to tell as temperature is low may show more benefit in the winter. But so far very happy 😃

My tub stays at or above temperature point with this inflatable. It seals the inside of the tub better than just the loose snap on cover.

The original inflatable cover got punctured during a move and it is impossible to care for the hot tub properly without it.