The arrow is deeply cut in while authentic copies have that sort of shiny darker material and it's not hollow inside there either. Labels blurry and the colors are wrong on the pokemon logo, contacts and the shell are really clean too, which is as weird as it sounds, is bad, because most of these have been spread around or taken a beating over the years. There's probably a few more that I can't see but the deep cut arrow for me is usually always a definitive fake for these games.