Westfalia grey plastic clips for holding Aluminium Louvre window mosquito net (C9578) in place. Sold as a pair.
It's a bit tricky to fit these clips:
The best way to fit them is from the middle point on the top edge. By pushing the middle point inwards, you can gain a small gap on the top. Please put both clips on the top edge through the little gap, then slide them towards both ends of the frame and they will be tightly holding the net.
Hope this is helpful.