The next-generation foldable devices from Samsung are anticipated to be introduced at a gathering in August, along with the company’s upcoming Galaxy Watch6 family. While we wait for summer to come, we’re learning more about the Watch6 family of devices, with the exception of the Pro.
Both the Galaxy Watch6 and the Galaxy Watch6 Classic will be available in two versions. 
A 300 mAh cell will be present in both the Galaxy Watch6 40mm and the Galaxy Watch6 Classic 42mm. A 425 mAh cell will power both the Galaxy Watch6 44mm and the Galaxy Watch6 Classic 46mm.
A recent rumor claimed that Samsung would bring back the rotating bezel this year speculating that it would happen for the Galaxy Watch6 Pro, but it could very well feature in the Classic line too, and thus the chunkier bezel is probably what explains the 2mm jump in size compared to the vanilla models.
