Firebelly’s head position feature gives you immediate audio feedback on your head position every two strokes.  Additionally, you can setup a threshold mode that only turns on head position feedback when your head position exceeds a preset target.

When you purchase the feature, you will be given a software license key that you can use to add the head position feature license to your device. After that, the feature is configurable via the Firebelly App. 

Note: The license key is valid per device.  If you are purchasing multiple devices, please add a license for each device you purchase.