- That's not your belt.
- No. It's a clever replica of The Joker's utility belt. He must've slipped it on me during the struggle.

13 seconds sound clip from Batman (1966) - Batman Is Riled (S1E6) TV Series.

You can hear this line at 00:13:42 in the Blu-ray version of the movie.

Quote context

[...]

- Try to explain that to little Harold kneeling beside his bed saying his prayers.

- Stand and fight, Joker.

- Let us away! Let us away!

- Holy Fourth of July! What's this?

- This was just the curtain-raiser. Next time you'll get the real showstopper.

- That's not your belt.

- No. It's a clever replica of The Joker's utility belt. He must've slipped it on me during the struggle.

- Then when you thought you were stopping him with your utility belt, he was really stopping us with his!

- That tricky devil! He's hit us below the belt!

- Golly. What do you suppose little Harold's going to think now?

- Crime wave grows! Police powerless!

[...]