Microsoft is currently preparing at least three new Windows Phone 8.1 devices for release this year, including a 4.7-inch midrange "Superman" handset, a low-end "Rock" device, and its "McLaren" flagship Windows Phone with the new 3D Touch features. Leaked photos posted to popular Chinese microblogging site Weibo suggest there could be another Windows Phone 8.1 handset on the way, which may fill the midrange gap and replace the Lumia 820. The mysterious device appears to use an aluminum frame with a polycarbonate back, a construction both the Lumia 925 and Lumia 930 use. WPDang speculates that this could be the Nokia Lumia 830. It's also possible this is Nokia's "Tesla" handset, a midrange device that could be dubbed the Lumia 730 when it launches.