Sony released the Xperia Z5 series loaded with top notch features in selected regions across the globe. This variant was not available in the US till now. However, the "Sony Xperia Z5 Premium's" unlocked, international variant can now be purchased via Amazon and Expansys.
You should note that the Xperia Z5 Premium available via Amazon and Expansys won't come with U.S. warranty. The retailers have listed both single SIM and dual SIM options of the Z5 handset and both of the variants will support LTE connectivity. But, the handset will work only under AT&T, T-Mobile and other GSM network carriers, as CDMA support is not available.
Coming to price, Amazon's Xperia Z5 Premium will cost $733, whereas from Expansys the same can bought for $779.99. The USP of this smartphone is the 4K display resolution of 2160 x 3840 pixels. This device is reportedly the "world's first smartphone" with 4K display.
Specifications wise, the Sony Xperia Z5 Premium will boast a 5.5-inch IPS LCD display. The screen size along with 4K resolution translates to a magnificent 806 ppi pixel density resulting in outstanding viewing experience. The device is powered by a Qualcomm Snapdragon 810 processor backed by 3GB RAM. Although currently the OS is Android 5.1.1 Lollipop, it can be upgraded to Marshmallow.