


Mi Smart Band 4 measures 21.6mm in length and 10.8mm in width.

Mi Band 3's display measures 17.26mm in length and 9.66mm in width. * "39.9% larger display size" is in comparison to Mi Band 3.Actual results may differ due to to differences in environment, use and settings. * Mi Smart Band 4 lasts up to 20 days on a single charge according to Huami Laboratory testing: Tested using default settings, with 30 minute automatic heart rate monitoring enabled, receiving 100 notifications per day, 2 alarms per day, vibrating for 5 minutes, touching the touch button 10 times per day, and syncing with the app once per day.Mi Smart Band 4 water resistance report code: QT1902005 Testing performed by the National Quality Supervision and Inspection Center for Watches. Water resistance is in accordance with GB/T 30106-2013 standard.
