Didak Pool makes this cover to fit one pool size. The box puts it plainly: FIT OVAL POOL 4.27m x 2.50m. That is the oval above-ground pool this cover belongs on, and no other.
Using it is simple. When nobody is swimming, you lay the cover over the pool and let it fall over the top rail, as in the drawing on the packaging. That way less leaf litter, grass and dust blows onto the water at night and in the wind, and there is less to fish out with the net next time.
The box contains the cover only. The pool with its frame, legs and ladder in the packaging photo is there to show the fit and is not included. So measure your own pool before you order: 4.27 x 2.50 m is the size this cover is made for.
A practical buy for anyone who already has an oval above-ground pool in the garden, and for anyone who is due a new cover after a few seasons.