The Idea Tube is a community-created cosmetic item for the Engineer. It is a leather tube strapped to the Engineer's back which contains a rolled team-colored blueprint and a yellow ruler. It also sports a handle and a white Mann Co. logo printed on the lower end.
The Idea Tube was contributed to the Steam Workshop under the name "Top secret blueprints_v3".
- The Idea Tube was added to the game.
- [Undocumented] The Idea Tube was added to the drop system.
- Added Pyromania cosmetic items to the Mann Co. Store.
- [Undocumented] Added Strange quality.
- Both the Idea Tube and the Builder's Blueprints use the BLU version as the backpack image. Most items in the game show the RED team image (if team-colored). The nature of the 'blue'prints is most likely the reason why this is so.