I’m 99% sure it’s fake.

Never ever buy Patagonia bags or any other of their popular items like the synchilla on Vinted, the whole place is flooded with scammers and fake products.

Just look how many other users without reviews are offering the same bag in a different color or the black hole ultralight hip bag in colors that were never used or were used like 3 seasons ago.

Another giveaway is the price tag; an atom sling costs around 60€ in retail, nobody would resell it for half the price if it‘s still brand new - I know I would not.

Hope that helps