
Penny, we're in the red ZONE.
The Big Bang Theory Season 6, Episode 24

No, no, no, no.
The ZONE ZONE is a safe ZONE.
The Big Bang Theory Season 12, Episode 14

Stop saying "ZONE ZONE"!
The Big Bang Theory Season 12, Episode 14

Can't talk.
In the ZONE.
The Big Bang Theory Season 7, Episode 6

Look, I know this experiment is
a big step outside of your comfort ZONE.
The Big Bang Theory Season 10, Episode 4