Over the last couple of years, thin phones have become "a thing" again and for the most part it's devices from the East that are driving the taste in ludicrously thin devices. Sony's Xperia Tablet Z2 is only 6.4mm thick, which is incredible when you think about it, but Sony's tablet is a fairly wide device, so there's a lot of room to spread things out under the hood. Chinese manufacturer Vivo can do better though, as their X3S is just 5.95mm thick. At that sort of thickness, there's going to be compromises made, but for the most part this is a fairly solid smartphone at a good price.
The Vivo X3S features a MediaTek MT6592 octa-core CPU, a 5-inch 720p display, a 13-megapixel camera and a pretty small 2,000 mAh battery. As a result of using a MediaTek CPU, this is stuck running Android 4.2 as MediaTek hasn't updated their drivers or anything like that for Android 4.4.2 KitKat just yet. The 13-megapixel camera features a wide aperture at f/1.8, but it does bulge a little out from the rear of the device, which is probably how the X3S is 5.95mm thick elsewhere throughout the device.
Those outside of China are finally starting to get their hands on one of the world's thinnest devices, starting with Malaysia. The device has gone up for sale for RM 1,399, which is roughly $475 US. A pricey device for sure, but this is one of the better-looking devices to come out of China recently and features a minimal look with a metal build in places to deliver a premium feel. Of course, the MediaTek CPU means you'd be stuck with Android 4.2 and that display resolution could be better, but if you're looking for a fashionable device - and you live in Malaysia of course - then this could be a decent choice for your next device.