Did you think Huawei's Ascend P6 was a slim smartphone? It has nothing on BBK's just-unveiled Vivo X3. Despite a 5-inch (if 720p) screen, an 8-megapixel rear camera, a front 5-megapixel shooter and a 1.5GHz quad-core MediaTek processor, the X3 measures a wafer-like 5.75mm thick in its blue variant. There's plenty of party tricks under the hood, too -- the Android 4.2 device has both an infrared sensor for touch-free gestures and a dedicated audio chip from ESS. It also preserves much of the better hardware from its slower and thicker X1S cousin, including the 16GB of non-expandable storage and the 2,000mAh battery. The Vivo X3 ships to China on September 1st for the same ¥2,498 ($408) as the X1S. If the device proves tempting, you can check out the Engadget Chinese hands-on; their English-language video is available after the break.