This Pool Cover by Didak Pool is the rectangular version. The box reads FIT RECTANGULAR POOL 2.82m x 1.96m and repeats the long side as 282 cm, exactly the size of the above-ground pool the cover is meant to sit on.
After a swim you lay the cover over the pool; it drops over the top rail, the way the drawing on the packaging shows. Between two swims that leaves fewer leaves, less grass and less dust on the water.
You receive the cover, nothing more. The pool with its frame and legs in the photo is there to show how the cover fits and is not supplied. So measure your own pool first: 2.82 x 1.96 m is the size this one is cut for, and a cover in any other size will sit either too tight or far too loose.
For anyone who already owns a rectangular above-ground pool of that size and wants a cover made to match, rather than a universal tarpaulin.