Lumen Metabolism Tracker, Original Box and Accessories No Carry Case Weight Loss

Lumen Metabolism Tracker, Original Box and Accessories No Carry Case Weight Loss. Lumen measures your metabolic fuel usage specifically, whether your body is burning carbs or fat by analyzing the concentration of carbon dioxide (CO) in your breath. Its a metabolic analyzer. Note that you do need to subscribe to Lumen and pay for a monthly subscription to use the app. The lumen doesnt work without the app.