According to Samsung, the Gear S2 and Gear S2 classic were designed to cater to two distinct consumer preferences. The Gear S2 classic with a black finish and a traditional leather band for those who prefer a "timeless watch design" and the Gear S2 for "those on-go and have an admiration for minimal and modern design".
The Gear S2 and gear S2 classic both have a 1.2 inch circular screen with a 360 x 360 pixels resolution, NFC for mobile payments, Heart rate monitor, WIFI are powered by a 1.0GHz dual core processor with 512MB of RAM and 4GB of storage and runs Samsung's proprietary Tizen OS.
The Gear S2 and S2 classic also comes with a 3G variant which sports a first of its kind e-SIM, which eliminates the need to pop a SIM in order for it to work on 3G networks. The 3G versions of the Gear S2 and Gear S2 Classic allows for voice calls without the need for a phone.
The Gear S2 will be available in a Dark Gray case with a Dark Gray band and a Silver case with a White band. The Gear S2 classic will be available in a Black case with a Leather band.
Source: Samsung Mobile Press