<p>All files will be deleted once BT Cloud is closed. If you want to keep your files, make sure to <a href="https://www.bt.com/help/broadband/bt-cloud/getting-set-up/download-or-access-files/how-do-i-download-files--folders-and-devices-from-bt-cloud-">download them before 31 October 2024</a>.
The outer sleeve measure 5.5mm on my micrometer this would suggest that the inner is probably 2.1mm but my micrometer is not fine enough to measure inside accurately.