In addition to the Sony Xperia Z4 Tablet that is tipped to come at the MWC 2015 expo, the company is likely to announce a new water-resistant handset the Xperia M4 Aqua. This would be the successor to the Xperia M2 Aqua that was unveiled last year.
Not much details regarding the handset are currently available though it is being said that the device would be running the Android 5.0 Lollipop out-of-the-box. However, there are expectations that just like the M2 Aqua the Sony Xperia M4 Aqua would also be a mid-range handset with LTE connectivity and with the most highest water-proofing certification available the IP68 that would allow the handset to remain in 1 meter water for more than 30 minutes.
All our eyes are now at the MWC 2015 expo from where we would soon get you with official details.
source: Xperia Blog