2043B radio

Radio is a Fallout and Fallout 2 item.

Fallout
The radio may be used to cause a diversion among the Super Mutants patrolling the outer regions of the Northern Military Base, allowing the player easier access to the base's interior. Attempting to use the radio in other locations elicits a squeal of unintelligible static. It can also be linked with the computer that controls the forcefields within the military base giving you remote control over them.

Fallout 2
In Fallout 2 the radio can be used to help Vic to repair radio and be able to free him from Slavers.

Locations
In Fallout, this item can be obtained by barter from Lars, the head of the guards near the entrance of Junktown. Lars' price is about half of what Mitch charges at the All-N-One store in the Hub.