6.45 inch Windows Phone reference model introduced at Computex
The 7 inch Android powered Samsung Galaxy W currently is the phone with the largest screen, followed by the Wistron Tiger Windows Phone. The ZTE Nubia X6 and the Sony Xperia Z Ultra both are next, each with a 6.44 inch screen.
You can see the phabet-sized device in action by watching the video below. Hopefully, your German is up to speed.
source: MobileGeeks.de via WMPoweruser