Microsoft has unveiled its first wearable device that can track a user's sleep and exercise as well as connect to a health service on smartphones.
The Microsoft Band will retail for $199 (£125) on the company's online store.
The device can operate for two days on a single charge and has 10 sensors that can track heart rate, calories, stress and even a person's sun exposure.
It marks Microsoft's latest push into digital health after its medical record initiative HealthVault in 2007.
"This is just the beginning of a multi-year vision for Microsoft in the health & fitness and wearables category," the company said in an emailed statement.
"We want to enter this space in a deliberate and measured fashion and as such are launching first in the United States."
Technology giants Apple, Samsung and Google have all released health initiatives and are looking to further develop the growing demand for wearable devices.
However, Microsoft's device is distinctive because it will work with all major mobile operating systems as well as connect to social networks such as Facebook and Twitter.
"Consumers now have an overwhelming choice of health-related cloud platforms to choose from," Ben Wood from CCS Insight told the BBC.
"They can be forgiven for being confused by the multitude of options. It's going to be a tough decision to choose whether to place their loyalty with Apple, Google or Microsoft given the immaturity of all three platforms.
Furthermore, once they choose a platform they risk locking themselves into a long term commitment if they want to keep a lifetime of health-related data in one place."