The two letters after the product name of the FRITZ!Repeater on the type label are used to distinguish the Wi-Fi network of your FRITZ!Repeaters from the Wi-Fi network of an identical FRITZ!Repeater model.

In the factory settings, the FRITZ!Mesh Set already has individual Wi-Fi settings that are printed on the type label. This way, all FRITZ!Repeaters from the set already have the same unique Wi-Fi network key out of the box and they are already protected from unauthorized access when they are used for the first time. The Wi-Fi network name (SSID) is made up of the product name followed by two randomly generated letters (for example 'FRITZ!Mesh Set 4200 XY'). If you do not want to use the FRITZ!Repeater's factory settings, you can simply change the preset name of the Wi-Fi network.