How do I know it's authentic

Kind of a hard question to answer since there isn?t one simple one answer. Here are some things to look for: 1) Buy from a reputable well know brick and mortar on-line store; if buying from Ebay make sure the person has been selling for at least six months with few, if any bad ratings. 2) If the price is way lower than the open market is charging then it?s probably stolen or counterfeit, none of which you want. 3) Check out the packaging, Logitech?s printing and packaging is very professional looking. If you have a cheap box/CD and poor printing you probably have a counterfeit. Good luck and please don?t forget to rate this post.

• Download Logitech Gaming Software and install the software in your computer.
• Plug in the Mouse. The software will detect and display the information about the mouse.
• There is another way, after the pc installed the driver, check devices and printers. You will see the MX518 ( as picture)

Thx tomj23, I have searched over internet and found another possible solution, it might be true, which is under your "device manager", found "mouse", if it's genuine, then it will show the name with the word "logitech" on it, if's fake, then it will just have some other words showing like "USB devices"