You’ll need an activity tracker and Continuous Glucose Monitor (CGM) to collect the biometrics — like heart rate, activity level, and glucose — that enables us to provide personalized insights and recommendations based on your unique physiology. We will run through the process of getting a CGM together during sign-up, but you’ll need to purchase an activity tracker on your own if you don’t already have one. January is compatible with most popular activity trackers, including all Apple Watch models, Oura Ring Gen 2 and Gen 3, and all Fitbit trackers (except Ace 3).