This USB button helps Jeopardy! contestants get their buzz on

An arm grasps a fist-sized round black metal rod with a glowing red button on top, just underneath the thumb.

Many Jeopardy! contestants say they used this button to practice buzzing in before the show. | Photo by Amelia Holowaty Krales / The Verge

In Jeopardy, the button is almost as important as the answer.