What's the meaning of the number next to the 3rd generation key of Mercedes-Benz?

Refers to the serial number of the key.

The number of the car key is used to match the new key and represents the serial number of the key, that is, the serial number of a car.

Mercedes-Benz is a world-famous luxury car brand. 1886, 1 In June, karl benz invented the world's first three-wheeled car, obtained a patent, and was praised as the inventor of the automobile.