You can check the back of the watchโif itโs a genuine Casio, it should have a serial number. Also, fake watches usually have a bulkier back, while the original ones are slimmer. Pay attention to the second dial too; there are noticeable differences between real and fake versions. Please visit a showroom, Helios, or any trusted physical watch store to examine the watch in person before buying. I made the mistake of chasing discounts and regretted itโdonโt do the same.