Polar M400 vs. Xiaomi Mi Band 2 vs. Michael Kors Access Sofie vs. Xiaomi Mi Band 4
 | | | | |
| PolarM400Remove Buy Now | XiaomiMi Band 2Remove Buy Now | Michael KorsAccess SofieRemove Buy Now | XiaomiMi Band 4Remove Buy Now |
Basic Info | ||||
| Suggested Price | $200 | $23 | $395 | $25 |
| Release | 2014 | 2016 | 2017 | 2019 |
Activity & Fitness | ||||
| Calories | ||||
| Cycling (Bicycling) | ||||
| Distance | ||||
| Heart | n/a | |||
| Oxygen | ||||
| Sleep | ||||
| Steps | n/a | |||
| Swim | ||||
Battery | ||||
| Duration | 8 hours to 30 days | 20 hours | 1 day | 20 days |
| Rechargeable | ||||
Compatibility | ||||
| Android | ||||
| iOS | ||||
| Windows Phone | n/a | |||
| Mac | n/a | |||
| Windows | n/a | |||
Connectivity | ||||
| Bluetooth | ||||
| Cellular | ||||
| GPS | ||||
| NFC | ||||
| Wi-Fi | ||||
Display | ||||
| Color | ||||
| Resolution | n/a | n/a | 390 x 390 1.19 inches | 120x240 |
| Size | n/a | 0.42 inches | 0.95 inches | |
| Touch | AMOLDED | |||
| Type | n/a | OLED | AMOLED | |
Functions | ||||
| Audio Speaker | Alerts only | |||
| Clock | ||||
| Phone | ||||
| Vibration | ||||
| Voice | ||||
Hardware | ||||
| Accelerometer | ||||
| Barometer or Altimeter | ||||
| Ultraviolet Sensor | ||||
| Water Resistance | 3 ATM | IP67 | 1 ATM | 5 ATM |
Notifications | ||||
| Phone | ||||
| Emails | ||||
| Texts | ||||
Software | ||||
| Operating System | n/a | n/a | Android Wear 2.0 | AMAZFIT OS |
| Apps | ||||
| Music | ||||