Samsung appears to be readying two new wearables, with model numbers SM-R365 and SM-R600. The latter recently popped up on Bluetooth SIG, while the company has accidentally listed the SM-R365 on its official website, which appears to be called Gear Fit 2 Pro.
There is very little details about both devices. The Gear Fit 2 Pro might be an improved version of the current Gear Fit 2 with a similar design, but better specifications and improved step-tracking accuracy. It's said to be made official around the same time as the Galaxy Note8.
Regarding the S-R600, the wearable is dubbed as Gear Sport and has been cleared by the FCC. The only thing we know about it is it will have a heart rate sensor.