A cage constructed of utterly unbreakable jet-age plastic.
6 seconds sound clip from Batman (1966) - Zelda the Great (S1E9) TV Series.
You can hear this line at 00:13:10 in the Blu-ray version of the movie.
Quote context
[...]
- Well, since you can't pay my price of one hundred thousand dollars, I hardly see the point.
- Behold, Eivol Ekdal's inescapable doom trap.
- A cage constructed of utterly unbreakable jet-age plastic.
- Before you get inside you will demonstrate. I'll show you. Duck behind the trunk.
- Oh, it's fantastic. The plastic isn't even scratched.
- Of course, I told you. It's unbreakable.
[...]