Sony is expected to announce a new smartwatch and three Xperia smartphones at the Mobile Asia Expo show on June 25. One of those smartphones is expected to be the highly anticipated 6.44-inch Xperia Z Ultra. The device will be Sony's first phablet and leaked images show that it will support the rumored standard pen/pencil input and will be offered in a choice of a black or white model.

When information about the Xperia ZU first leaked, it was reported that Sony was going to release a phablet that would be larger then the 5.5-inch Galaxy Note 2 and would allow users to use a standard pen or pencil for input in place of a stylus. The leaked images seem to confirm that information by showing a pencil being used on the smartphone's display. The ZU is expected to use a scratch-resistant display and also follow the Xperia Z and Tablet Z by being both water and dust-resistant.

The leaked images also show the back of the smartphone for the first time. The ZU will have a curved back instead of the completely flat design found on the Xperia Z. The photos also show a white model that has not been seen before. The source claims that Sony has used a magnesium material for the case and will offer the smartphone in choice of black, white, and possibly purple, although a purple model is not shown.

The Xperia Z Ultra has some very impressive specs. It will feature a 6.44-inch 342ppi (pixels per inch) 1920 x 1080 Full HD display using Sony's Triluminous and X-Reality Engine technologies, will run Android 4.2.2 Jelly Bean, be powered by a 2.2GHz quad-core Qualcomm Snapdragon 800 processor with Adreno 330 graphics, 2GB of RAM, include 16GB of internal storage, an 8-megapixel rear camera, 1.3-megapixel front facing camera, Wi-Fi 802.11 a/b/g/n, Bluetooth 4.0, GPS, a microSD expansion slot with support for up to 64GB cards, and a 3,000 mAh battery.

The Xperia ZU is shaping up to be one big, tough, and powerful smartphone, but we'll have to wait until June 25 to hear all of the official details from Sony.