Lief has an “airplane mode” where all radio transmissions are turned off. It’s accessible in the Lief app’s Settings. You won’t be able to see real-time data in the app, which is transmitted over low-energy Bluetooth, but the device’s autodosing features will still work fine. In order to sync your data with the app, you’ll need to connect for a few minutes at the end of your wear time. You’ll be able to tell the data is syncing because your HRV bar chart will fill out for the hours you were wearing Lief. For more information on EMF exposure, please refer to this Healthline article.