In the 80's & 90's Oakley Blade & Razor Blade sunglasses had/have patent numbers molded into the cross/main frame section and also the arm pieces(all styles of arms). All the fake Oakleys do not have patent numbers molded into the frame/arm pieces, so if your trying to buy the old school vintage stuff keep that in mind. Sorry about the small pic size (can't figure out how to make it bigger), but look at the bottom right pic, and you might be able to see the arm is real but the frame is not. Their should be a patent number on the thick inside part of the frame. Plus note how badly the arm fit on the frames "nub".You might ask the seller for the patent numbers off the frames and arms. Hope this helps.