In the world of wrist wear, the Rolex is basically the sports car of the watches. You can bet that it’s durable, efficient, and a very good investment if you’re wearing a Rolex—that is, if it’s a REAL Rolex on your wrist.

These days, counterfeiting high-end items is a very lucrative trade, and of course, the Rolex is not exempt to the hordes of people who are looking to cash into the Rolex name, hoping to make a quick buck. If you’re purchasing from a licensed Rolex seller, then you can probably be sure that you are buying a genuine Rolex, but what if you’re buying online, or from a collector that you only recently met, you want to make sure that you’re buying the real thing. This goes double if you’re going for vintage Rolex watches, which are usually more expensive and “hard-to find” (thus, harder to authenticate), compared to more modern versions.

Here are five methods that you might want to keep in mind to see if you’re buying a genuine Rolex watch:

• Magnification

One of the most easily recognizable traits that a real Rolex has is the magnified date display. Rolex watches display the date on the watch face near the 3:00, and since it can be hard to read, a real Rolex watch will magnify this display via a “Cyclops” lens. This lens will magnify this to 2.5x resolution. This is a difficult trait to counterfeit, so some cheaper knockoffs will only magnify it by 1.5x, and even cheaper versions won’t even have the Cyclops lens at all. If the date is not magnified at all, then you can be sure that particular Rolex is a fake.

•    Model Number

If you have the time and access to the Internet, you can check the model’s serial number before purchasing it. There is a trick that many Rolex counterfeiters use to trick unwary customers into buying a cheap Rolex expensively: they switch out the material in an expensive model to cheaper metals, but keep the price the same. For example, the Rolex President series are only made from gold or platinum if they display the date and the day on the watch face. If you find a Rolex President that is made from other metals, it is a fake.

• Engraving

A true Rolex will have crisp and clear engraving on the metal, whether it’s on the dial, the watch face, or the back of the watch. The writing should be clean, convex, and pristine. You should ask for a magnifying glass and check for even the most minute mistake or problem in the writing. Spelling mistakes, unclear engraving, or bubbling on the watch surface are clear signs of a fake Rolex.

• Water Resilience

Yes, this is a pretty extreme test, but if you’re dealing with a real Rolex, a quick dip in water (around 3-4 seconds) won’t be a problem. Unless you’re buying a Rolex Submariner (which is actually made for deep-sea diving, which in that case, dunk it all you want in water), all real Rolexes are water-proof and sealed. Those 3-4 seconds would be enough for water to get into cracks in the watch’s seal, and if you find any leaking in the dial or the watch face, it is a fake Rolex.

• It’s All in the Details

The beauty of the Rolex is that it features small details from which you can tell that there is a lot of love and care in making these Rolex watches. A real Rolex has a smooth, uninterrupted movement of the second hand, and it does not tick at all. The inner gears of a genuine Rolex are so perfectly in sync, that the movement is perfect.

Remember, if you find a watch that fails even ONE of these criteria, it is NOT a real Rolex. Take the time and effort to find a real one; you will be glad for the investment!