If you are not sure that your device supports 4G, you should check whether your smartphone or tablet has the option 'LTE'.
The Telenet Group network currently uses a frequency of 1800 MHz. Therefore, make sure that your device also supports this frequency - especially if you want to buy your device abroad. You will find the frequencies of your device under device specifications, in the manual or on the manufacturer's website.
Your device will not always automatically connect to the 4G network. It is therefore recommended to check or adjust your settings for mobile Internet.