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
Amazon.com: Fitbit Charge 5 Advanced Health & Fitness Tracker with Built-in GPS, Stress Management Tools, Sleep Tracking, 24/7 Heart Rate and More, Black/Graphite, One Size (S &L Bands Included) : Electronics
Fitbit Charge 2 review: a promising fitness tracker, plagued by bugs - The Verge
Fitbit GPS vs Connected GPS: how to use GPS on your Fitbit and see your routes - MyHealthyApple