This is official stock Sony Xperia firmware
Model: Sony Xperia M4 Aqua Dual (E2312)
Firmware version: 26.1.B.1.85_R8A
Region: Singapore (Generic) [1293-8829]
Android version: 5.0
Download Here
Warning...!
Always backup before flashing..!
I'm not responsible for any damages will be held!
Do at your own Risk!