I was just looking at this yesterday. Unfortunately, there is like no sizing information at all on the website. Which is a drag because this stuff isn’t sold in stores, so no chance of trying anything on.
I actually stumbled upon that jacket while shopping for underwear. The Odin X Target shelves were pretty bare, with only one jacket and a few questionable black plaid shirts remaining. Quantities are limited, and I don’t expect stores to restock, but it’s definitely out there.