Rado watches are expensive, so if one is presented for a cheap price, it's probably a fake. Real Rado watches are made from quality ceramic materials, while counterfeit ones are not.
The screws on the back of a genuine Rado have straight slots, while most fakes have cross-slotted screws on the back. Fake Rado watches are gold-plated, whereas real ones are never gold-plated. Real Rado watches have the word "Swiss" with three Arabic symbols on the face. Counterfeit models say "Swiss Made" or "Swiss Movement" at the six o'clock point on the face. Lastly, real Rado watches are registered with the manufacturer and can be verified using a serial number on the clasp.