available for free to you (as is) are the rejects from my first attempt at creating a magnetic window screen:
poorly assembled window screen (~4' x 4'). there are no documented holes in the screen. the mesh is good and should not need patching.
25' unused adhesive magnetic strip (you would need at least 16' of this to affix the 4'x4' window screen to a window)
leftover mesh bits
four plastic "corners" for the screen
negligible amount of white plastic adhesive strip (the top part of the plastic + mesh + magnet sandwich. used so that the mesh adheres better to the magnetic strip and any adhesive exposed by the mesh doesn't collect dust
the poorly assembled window screen could be usable as is (with a bit more adhesive) but the corners are not quite perpendicular and the magnetic strip is falling off a bit at one corner. it would certainly look prettier if you redid it, but it's serviceable as is and I certainly successfully used it for a while like this.
there are not enough materials to simply remake the screen in a smaller size unless you provide your own plastic strips (or forego the final level of the screen sandwich), but there are enough materials to affix this screen to an opening as-is. or you could properly disassemble the screen and reuse the materials to remake it different. or you could use these materials in combination with a purchase of a new screen kit to make a mega big screen. I thiiiink this is the one that I bought (if you need me to be certain let me know and I'll check): https://www.amazon.com/dp/B08T1J1N4R/
you must take the 4ft x 4ft window screen (that's both the most unwieldy bit and the bit that has the greatest possible future uses imo), but if you don't want any of the other bits let me know and I'm happy to keep them.
I realize that the screen technology is a bit confusing. please let me know if I can clarify/please contact me with any questions. :)