Guppel is a brand of diamond company, with excellent quality and price. Click "Product Anti-counterfeiting Inquiry" in official website of Diamond Cooper Jewelry Co., Ltd. and enter the product anti-counterfeiting inquiry system of Diamond Cooper Company, and you can find it. If you can't find it, you can call the phone published on the Internet or send a short message with your mobile phone. There are not only product information, but also product pictures, prices and the authenticity of the inquiry voucher. It is not reliable to check certificates on other websites, telling you that most certificates are fake brands!