Image Source: Keller Sports' online store, which is showing the device as currently not for sale.

Adidas could soon add a new activity tracker to its product line, a wristworn wearable called the miCoach Fit Smart, according to a report from Engadget.

A letter Adidas wrote about the miCoach Fit Smart to the FCC in May 2014 explains that Adidas wants the device's external photographs, internal photographs and user guide to stay private for at least six months, so the device could be announced as early as November of this year.

In a trademark filing Adidas posted, the company explains the Fit Smart will track "heart rates, calories burned, time, duration, stride rate, pace, speed, distance and steps taken". It also suggests that the device will connect to a companion app that provides coaching through "visual and haptic feedback".

Images of the not-yet-announced device have also appeared on online store Keller Sports.

Adidas' new device has a slight resemblance to longtime competitor Nike's wristworn activity tracker, the Nike+ FuelBand, although there's speculation around how long Nike's tracker will be in production. So far this year, Adidas has amped up promotion of its activity tracker line.

Last month, Adidas VP of Innovation Qaizar Hassonjee said the company equipped 19 teams in the United States and Europe with its miCoach Elite system and several teams that have been training with the system in the World Cup. During their games, he continued, the soccer players will actually wear jerseys with built-in sensors, as well as a “player cell” tucked into a pocket in the back of the jersey.

During the Google IO keynote this week, Google Play Product Manager Ellie Powers announced that Adidas would be a partner for Google Fit, a new fitness platform for digital health app and device developers. She added that Adidas has a collection of smart sensors that they are opening up to developers for the first time.