Sheldon: H-O gauge trains are 1/87th scale. N gauge are 1/160th scale. And that brings us to Z gauge, at a - you could easily swallow it, dont ask how I know - 1 to 220.
Bernadette: I'm sorry, I have to ask.
Sheldon: When I was five, I ingested a Z gauge locomotive. I spent the next three days saying, "I think I can pass it, I think I can pass it, I think I can pass it."