Leaked images of the FitBit Charge 2 and Flex 2 hinted of some changes in the fitness trackers, the most obvious of which is a much larger display.

According to the latest news, a new addition to the FitBit Charge2 is the PurePulse technology which tracks the heart rate of the wearer. This wasn't found on the first-generation device but was included in the FitBit Charge HR.

As to the specs of the FitBit Charge 2, a new feature of the wearable device allows you to link with your smartphone. It will also have 24-hour sleep and activity tracking, multi-sport monitoring and bands that you can change depending on your mood.

The leaked news about the FitBit Flex 2 reported of specs that include 24-hour activity and sleep-tracker. Unlike the FitBit Charge 2, this one has no screen display.

The second-generation Flex is also waterproof up to several meters, which is good news for those who love to swim as an exercise. This is an entirely new feature as the first-gen wearable is only sweat-resistant.

MacRumors said that the specs of the FitBit Charge 2 and the FitBit Flex 2 don't really differ too much from their predecessors. However, there could also be some changes to the two devices from the leaked info as the the release date expected to be in the holidays.

Fitbit CEO James Park previously said that they would be releasing new products this December during the second quarter earnings call. These products are presumably the FitBit Charge 2 and the FitBit Flex 2, according to the news report.