I bought it in size M, but it has such a narrow fit that it could easily be XS. It was tight on the back, uncomfortable in the armpits, and the zipper needed another 6 inches to close. I couldn't wear it and of course, I returned it.
The L size has a very small difference (1.5 cm on the back) and I doubt if that would fit me either. I preferred to replace it with another product.
It is made of recycled polyester and seemed to be of good quality and well-insulated, but I can't say more, I don't want to take any risks!!!