Question: what is the difference between mi band 2 and 3?
Answer: The biggest noticeable difference between Mi Band 2 and Mi Band 3 is the screen size. The Mi Band 2 sports a 0.42-inch OLED panel while the latter features a much larger, 0.78-inch capacitive OLED display. ... The Xiaomi Mi Band 3 also includes a heart-rate (PPG) sensor and carries a triaxial acceleration sensor.