M400 memory storage and notifications
M400 has a 4 MB memory. It can store up to 30 hours of training with GPS and heart rate, depending on your language settings.
When M400 memory is low, the device informs you with memory low notifications. After receiving a notification, it is recommended to sync your M400 with the Flow web service or Flow app.
1 h of memory left. Oldest session(s) will be overwritten.
Your oldest session will be overwritten when the memory becomes full.
Memory low. Please sync M400 with flow.polar.com
Sync M400 with the Flow web service to make sure your oldest training data is not lost when the memory becomes full. You can only delete sessions that have not been synced to Flow app or the Flow web service.