If the answer is METAL,
it's not exactly groundbreaking.
The Big Bang Theory Season 6, Episode 3
JON CARLOS: We'd use
METAL barriers
Westworld Season 3, Episode 8
Although I am getting
a little machine oil, I think it's METAL.
The Big Bang Theory Season 9, Episode 18
PVC comes here. Maybe a little
corrugated sheet METAL as a radiator here.
The Big Bang Theory Season 1, Episode 2
Sink your METAL deep
Game of Thrones Season 3, Episode 6