The design of the Sony Xperia M4 Aqua is quite similar to the Xperia Z3. As per the Xperia Blog ,It also has the protection at the corners, a separate trigger for the camera and the characteristic power button.
Sony xperia m4 Specs as a 5.2 inch display with 720p resolution, 2GB of RAM, a 13 MP camera and a 5 MP front camera. Snapdragon 610, 1.5 GHz processor is suspected.
The performance will take place with some certainty on March 3 at Mobile World Congress.Xperia M4 Aqua is will be available sometime in 2015 and price will be between 225 to 280 USD (In Sri Lanka it will be 45000-55000 Sri lankan Rupees)