The Seattle Mariners are the first MLB team to partner with smart ring manufacturer Oura. The club will primarily use the ring to analyze the relationship between a player’s performance and quality of sleep.

Oura has existing deals with the NBA, NASCAR, and UFC. The smart ring tracks biometrics such as a user’s temperature, heart rate, heart rate variability and respiratory rate. It studies those metrics to calculate a user’s daily sleep score.

“I use my Oura Ring every day to track my recovery. I rely heavily on feedback from my ring when I make adjustments to my workouts, diet and supplements,” Mariners outfielder Mitch Haniger said in a statement.

As a result of the coronavirus pandemic, Oura devised a Risk Score. The feature aggregates data such as heart rate variability and respiratory rate for the purpose of notifying a user if their body might be showing signs of illness.