Predators captain Roman Josi has made the Q-Collar part of his regular gear this season, but what exactly is the device?

You may have noticed something around Roman Josi's neck at Nashville Predators games. Here's what it is and the science behind it.

(NEXSTAR) – If you’ve been watching any NFL games recently, you might have noticed some players sporting white (or in some cases, black or blue or red) horseshoe-shaped collars around their necks.