It only appeared behind glass at the opening of Mobile World Congress in Barcelona and Samsung has remained tight-lipped about how much it'll cost and when we can actually buy one. 

The ring was shown off in three colors, including the gold band seen here.

This is the silver version.

And here is the steel-colored model, although under the lighting of Samsung's booth it's difficult to tell it apart from silver. 

It's possible to see the sensors inside the ring. They'll allow it to track your heart rate at day and during sleep. 

It also tracks movement during sleep, along with things like respiratory rate and menstrual and fertility cycles. 

It pairs with the Galaxy Health app to sync data and give you a "My Vitality" score, along with tips to improve your sleep. 

The ring will come in nine different sizes.

The larger sizes will feature a larger battery.

It's not the first smart ring. The Oura smart ring has been around for some time and offers similar tracking features.

The gold version looks a bit like a wedding band.

It looks quite slim.