Can Meross devices be used with my Fritz!Box?

In theory, Meross devices can be used with all standard 2.4G WiFi signals. In fact, some routers (such as Fritz!Box) have special features. When you activate MAC address filtering, the router will automatically open the "Restrict Wi-Fi to known Wi-Fi devices" in the submenu item "Security", then you need to manually switch it back to "Allow all new wireless devices".