Atrial Fibrillation (Afib) cannot be measured manually. When this feature is on, the device will automatically monitor your hearth health in a calm and quiet state. 

Please note:

• Activating AFib can reduce the battery life of your device.
• It will take six (6) hours to effectively begin monitoring, as the watch will monitor and collect atrial activity to establish baseline parameters. Once the six (6) hours have passed, the result will be visible on the App.
• The AFib service is only available if you have an active monthly subscription.