Currently supported devices: Mi Max / Mi Max Prime / Mi 4i / Mi 3 / Mi 4 / Mi Note / Redmi 1S / Redmi Note 4G The following devices will be receiving the update progressively starting from 20th Feb 2017: Redmi 2, Redmi 2 Prime, Redmi Note 3 Qualcomm, Redmi Note 3 Special Edition, Redmi Note 4 MTK, Redmi Note 2, Redmi Note Prime, Mi 2/2S, Mi 5, Mi 5s, Mi 5s Plus, Redmi 3/Prime, Redmi 3S/Prime, Redmi Note 4 Qualcomm, Redmi 4A, Redmi 4, Redmi 4 Prime, Redmi 4A, Mi MIX ::: http://en.miui.com/thread-508000-1-1.html
MIUI 8 Global Public Beta Supported Devices Redmi 1S, Redmi 2, Redmi 2 Prime, Mi 3, Mi 4, Redmi Note 3 Qualcomm, Redmi Note 3 Special Edition, Mi 4i, Redmi Note 2, Redmi Note 3G, Redmi Note 4G, Redmi Note Prime, Mi Max 32GB, Mi 2/2S, Mi 5, Mi Note, Redmi 3/Prime, Redmi 3S/Prime http://en.miui.com/thread-370585-1-1.html
