Why?

 

With the NBA resuming its season, there is still a concern about players contracting Covid-19. Although the players will be isolated at Disney World, the NBA still wants to ensure its participants’ safety. That being said, the NBA has partnered with Oura, a company that has distributed state of the art rings that track sleep, pulse, movement, heart activity, and temperature. Players have been instructed to wear the ring at all times as it will help track possible symptoms of Covid-19 three days in advance with ninety percent accuracy. 

 

https://www.cnn.com/2020/06/21/health/nba-smart-ring-tracking-covid/index.html