From Team Fortress Wiki
The Boston Boom-Bringer is a miscellaneous item for the Scout. It is a gray, orange, and team-colored boombox that is strapped on top of the Scout's default messenger bag. A hidden attribute makes this item play music during any taunt the player performs, though this effect was noted on the official TF2 website.
- The Boston Boom-Bringer was added to the game.
March 26, 2012 [Item schema update]
- This item can now be found in random drops.
- [Undocumented] Lowered the price of this item in the Mann Co. Store.
- [Undocumented] Fixed the Boston Boom-Bringer not playing sounds when in MvM games.
- When starting a replay with this item equipped, all of the boombox sounds will play at once.
- The description is a reference to the 1985 LL Cool J song "I Can't Live Without My Radio".
- The initials on the sticker on the back of the boombox refer to the Massachusetts Bay Transportation Authority, a reference to the Scout's hometown.