This is the Solar Pool Cover from Didak Pool, named on the box in English as 'floating solar pool cover'. The icon on the packaging says what it belongs to: 'fit rectangular pool', 4.00 x 2.11 m.
The cover itself measures 376 by 199 cm and is therefore deliberately a little smaller than the pool, so that it keeps floating free on the water surface. Didak describes the material as insulating bubble film: a blue film full of small air pockets that catch the sun and pass that heat on to the water underneath. The box puts the same idea in a drawing, with a sun and arrows going through the surface.
In use it is straightforward. Lay the cover on the water when nobody is swimming and roll it off again before going in. Nothing has to be fastened; it floats by itself.
Mind what exactly you are ordering: this is the cover alone. The pool in the packaging photo is scenery. Measure your own pool before choosing — separate sizes exist for other dimensions and for round and oval pools.
