Note The serial number consists of a letter followed by six characters (e.g. gxxxxxx). The MAC address has the following format: 70 : ee : 50 : xx : xx : xx. You can find the serial number / MAC address of the Classe 300 EOS: - in the device settings menu / General - in the app settings menu / My products / Class 300 EOS name. - on the label on the back of the product