Finland-based Oura has generated some considerable investor attention with its eponymous sleep-tracking ring. The company, which was founded in 2013, has brought in $28 million in a Series B funding round.

Made of titanium and featuring an accelerometer and gyroscope, NTC temperature sensors, and infrared LEDs, the Oura is designed to measure users’ activity both while they’re awake and when they’re sleeping, offering a holistic picture – via a mobile app – of their overall health with metrics like “Efficiency” and “Readiness”, as well as logs of how long users spent in REM sleep as opposed to deep sleep. The ring can also retrieve data from Apple Health and Google Fit.

Oura’s Series B funding round saw contributions from Forerunner Ventures, Gradient Ventures, and Square; executives from Forerunner and Square also appointed one new member each to Oura’s board of directors, while Gradient appointed a board observer.

Oura had previously brought in $20 million in funding from celebrities including Lance Armstrong, Shaquille O’Neal, and Will Smith; now, its institutional backing may lend the company further credibility in the wearables space.

The company’s Oura rings are already available, with CEO Harpreet Singh Rai asserting that 150,000 have been sold since they officially launched in 2018. Going forward, the company says it will be focusing on development of its website and a web portal for users, and academic partnerships.

Sources: VentureBeat, TechCrunch