In recent years, Luxottica has decided to utilize manufacturing facilities outside of the United States. As a result, most Oakley frames are no longer stamped with "made in USA" on the inside of the ear stem. Traditionally, the stamp was one way to authenticate Oakley's.
However, this is no longer the case due to the manufacturing change. Further information on this topic can be found on the FAQ page of Oakley's website or by calling their customer service directly. The item "Oakley Flak 2.0 XL Camo Matte Black Silver Icons Frame Only Authentic Rare" is in sale since Tuesday, March 30, 2021. This item is in the category "Clothing, Shoes & Accessories\Men\Men's Accessories\Sunglasses & Sunglasses Accessories\Sunglasses". The seller is "nicomacus" and is located in Clackamas, Oregon. This item can be shipped worldwide.