This useful product is made from a waterproof but breathable fabric with a sheepskin lining and tie-down straps.
It was designed both as a waterproof cover for a bedchair plus an alternative to a sleeping bag on those summer nights when even a lightweight bag is too hot. In fact you can use it without a bivvy or brollie yet still avoid any dampness from dew or even rain.
A further use I found for it was on cold, spring nights when turned upside down it makes a first class underblanket. You can also put it to the same use in summer with the open sleeping bag on top of you. This allows you to quickly respond to a run without having to unzip your sleeping bag.
I don't sleep out in winter and so rather than go to the extra expense of an additional heavyweight sleeping bag for spring and autumn I'll be sticking to my lightweight bag plus this bedchair cover. Thus the price of £49.99 could even pay for itself!