Alice Stancoil PROBE CoOBE
The BBC War Book instructed those staff designated to go into a regional bunker to take broadcast equipment with them from their parent radio station. The flexibility of the PROBE made it a likely item to be taken.

Just the facilities required
CoOBE stands for Comentator Operator Broadcasting Equipment.
Simplicity and flexibility of use are the keywords for broadcaster self-operated equipment. This unit gives the presenter just the controls they need to broadcast simple voice or, when a recorder was connected, pre-recorded pieces, without the burden of excess functionality that could confuse or impinge on their delivery.
In peacetime these units were used to provide radio commentary at football matches and other sporting events.

Truly portable
The PROBE could be powered by both batteries or mains power and connect to an ordinary telephone line, or a quality "music line", of the same type that were used to connect studios to transmitters.
Its weight allowed for easy transportation, so making it ideal to take to a WTBS bunker studio to augment the studio facilities or at a transmitter site to interface directly to the equipment there.
With its facilities fully exploited it was effectively a simple studio in a box.