Codenamed Lumia Saana, the 650 could become Microsoft's fourth Windows 10 handset, after the Lumia 950, Lumia 950 XL, and Lumia 550 (all of which are already available to buy in select markets around the world).
Apparently, the Microsoft Lumia 650 sports a 5-inch display with 720 x 1280 pixels, thus being larger than the Lumia 550 (which offers a 4.7-inch 720p screen), but smaller than both the Lumia 950 (5.2-inch Quad HD) and Lumia 950 XL (5.7-inch Quad HD). Other than that, there are no details on what else the upcoming smartphone will bring, though it's probably safe to assume that the rest of its features aren't particularly impressive.
While there's no word on when Microsoft is planning to release the Lumia 650, it's likely going to happen soon. We'll obviously let you know when we have new info about this handset.
source: Baidu (in Chinese) via Nokia Power User