The method is as follows:

The interior of the genuine IWC movement is clean, while the interior of the counterfeit IWC movement is not clean, with fingerprints, hair, and even copper shavings. The movement is secure within the components of the case. There will be clear and corresponding trademark words on the movement balance or inner plate of genuine IWC watches, while there will be no trademark words on the movement balance or inner plate of counterfeit watches, and if they are, they will be very rough and cannot be seen clearly. The trademark and writing on the dial and back cover of genuine IWC watches are clear and complete, while the trademark writing on the dial and back cover of counterfeit watches is blurred. The number of diamonds on the genuine watch and the number of diamonds in the movement will match what is marked on the dial. The number of diamonds on the dial of the counterfeit watch will not match the number of diamonds in the movement. The materials of genuine IWC watches and case materials match those marked on the back cover of the watch. The glass on the watch is clear and smooth, the edges and corners of the case components are not sharp, and the coating has no bubbles and will not fall off. The counterfeit watches have rough edges and corners, the coating is blistered and will fall off, and the accessories will also break.