Hi Rodrigo,
I'm not sure whether I understood it correctly or not.. Is it that you are referring about the browser device emulation??
If that is the case you can click the "Toggle device toolbar" option in the browser inspect element section (F12) as shown below..

If this is not what you intended, could you please share a bit more information about your use-case with us, so that we can help you better :)
Kind regards,
Benjith Sam