Fitbit Charge 4 Review: New running smarts tested inc. GPS, heart rate and Active Zone Minutes - YouTube
If you don't need GPS, the Fitbit Charge 3 is still the best fitness tracker for the money | Android Central
Fitbit Charge 4 Fitness and Activity Tracker with Built-in GPS, Heart Rate, Sleep and Swim Tracking, Black, One Size (Small and Large Bands Included) - Walmart.com
Fitbit Charge 3 specs leaked ahead of official announcement - PhoneArena
Fitbit launches $149 Charge 4 with GPS tracking
How do you turn on GPS for a workout with your Fitbit? - Coolblue - anything for a smile
Fitbit Charge 4 review: A better fitness tracker without the bulk - CNET