Official ROM K3 Note (K50-T5, K50-T3S), A7000 Turbo (K50a40)
Android 6.0 (S422 ROW) under Flash Tool
GAPPS included
No Rooted
Language support: Multilang
Inside there are instructions for installation
K50a40_S422_160315_ROW.rar\K50a40_S422_160315_ROW\DRV_Tools\MTK_flashtool_v5.1536.00.000\Koleosг********20150921.pdf
No Format All
Set in the Firmware Upgrade Mode
A source in the Lenovo-Forums.ru
P.S K50a40 full clone K50-T5