How to distinguish between water goods watches and high imitation watches? I checked on the official website, there is no model EF-550D-7A, the official price of the EF-550D series is over 2000 yuan. It seems impossible for Patek Philippe to be sold in stores for more than 500 yuan. If it's genuine when purchased online, it would cost at least over 1000 yuan. Besides, there are a lot of fake blue laser marks nowadays. OMEGA, a famous Swiss watch brand with full automatic mechanical movements from ETA, Patek Philippe couple watches. If you really like this watch, buy it at a specialty store or a reliable online store. The ones you mentioned for over 500 yuan or 200-300 yuan can be definitely identified as fake. Laser marks are not useful during warranty service; genuine products are always maintained through warranty cards. Additionally, when wearing the watch, it’s better to remove the laser mark on the back because some people might be allergic. Find the official Casio store. Without a laser anti-counterfeiting mark, it's fake, and if the warranty number cannot be found, it's also fake. My Patek Philippe Calatrava series watch was bought on Taobao. Fully automatic mechanical watches, self-winding ones, only cost 120 yuan with free shipping! Haha... After using it for over a month, it's currently working well. There's actually no need to buy an authentic one. However, most Casio watches under 200-300 yuan are genuine because most Casios are quartz watches, which do not have particularly high costs. Quartz watches are not good, it's recommended to buy mechanical watches, they are durable. Water goods are not necessarily fake; many are imported through unofficial channels and are much cheaper, basically around 55% to 65% off the official price. High imitation watches are basically fake, just very carefully made in appearance. For watches with complex functions, the functions of high imitation watches are not complete. For complex function Casio watches, if all functions are accurate, it can almost certainly be confirmed as genuine.