Official ZTE nubia Z9 mini (NX511J) Stock Rom ZTE nubia Z9 mini (NX511J) running on Qualcomm MSM8939 Snapdragon 615 with CPU Quad-core 1.5 GHz Cortex-A53 & quad-core 1.0 GHz Cortex-A53 and GPU Adreno 405 . These Stock Rom can use for Update/Downgrade firmware ZTE nubia Z9…