Samsung Gear S2 now available to buy in the US47
The Gear S2 and Gear S2 Classic are based on Tizen (not Android Wear), and sport 1.2-inch circular Super AMOLED screens with 360 x 360 pixels. They work not just with Samsung's Galaxy handsets, but also with a variety of non-Samsung smartphones running Android 4.4 or later and featuring at least 1.5 GB of RAM (here's a complete list of devices). While both the Gear S2 and Gear S2 Classic are water-resistant and feature rotating bezels (these help navigating through the UI), they look different: the Classic is called like that because it really resembles a classic timepiece, while the regular S2 has a futuristic design.
Later this year, a Gear S2 3G will also be available in the US (and other markets), but Samsung didn't say exactly when, and neither for what price.