The item is not available on the STEAM marketplace.
The Idea Tube
Team Fortress 2
Level 24 Backpack
Crafted by AWPtism
This handsome leather cylinder improves on the diary in every way. Do you have secret thoughts? Write 'em down, ball 'em up, and stuff 'em in the tube. It's incredibly easy to find a thought when you need it, too. Simply empty out the tube and there they all are. You're just one simple unballing away from remembering it.