what is the difference between xiaomi band 3 and 4?
The primary difference between Mi Band 4 and Mi Band 3 is the display. Mi Band 4 now comes with a 0.95-inch AMOLED display with 120×240 RGB resolution. This can provide about 400nits brightness with a 2.5D curved display. In contrast, Mi Band 3 came with a 0.78-inches OLED panel with a 128×80 resolution.