Google Fitbit Air
12 g with its band and up to 7 days of battery. No GPS, no screen, and no button, per The5krunner, so workouts rely on autodetection and the app.
What the maker states
| Smartwatch battery | 7 days, Battery life |
|---|---|
| Weight | 12 g, With band; 5.2 g without |
| Water rating | Water resistant to 50 m |
| Heart rate sensor | Optical heart rate monitor |
| App | Google Health |
| Subscription | Optional Google Health Premium, £7.99 a month after a 3-month trial |