at present, all the profiles are marked with anti-counterfeiting trademarks. If you touch them with your hands, the ones that have a sense of friction are fake. That's when you buy the finished inferior profiles after post-treatment and use the anti-counterfeiting machine at home. The genuine products are anti-counterfeiting before post-oxidation treatment, so there is an oxide film on the anti-counterfeiting surface. For those who are more professional, you can measure their film thickness and hardness (based on national standards) with an instrument. The thicker the hardness, the better the compression resistance and the corrosion resistance.