I'm not familiar with Amazon internals enough, but I doubt they keep SKU for every individual item, maybe for categories or types, so i.e. all the headphones of

I'm not familiar with Amazon internals enough, but I doubt they keep SKU for every individual item, maybe for categories or types, so i.e. all the headphones of the same model has the same SKU. Then it's enough to scan a single code on crate/bin/pallet which makes things far easier, but it's not sufficient to track down individual counterfeits.