I cannot remember which model this one is but I think it’s the ADV SKIN 5, if not it’s close to it. I have the Adv skin 5 in an XS and the difference is this one has a zipper pouch on each side in the front whereas the Adv Skin 5 in my XS does not. I prefer this model of vest but it’s a Small so it’s too big for me and rubs on my neck wrong. It’s in great condition, so I’m open to reasonable offers. ( I only wore for 2 trail runs, functionality wise it is wonderful! )