Run, bike, hike and more phone-free?and see your real-time pace & distance?with built-in GPS. Then check out your workout intensity map in the Fitbit app Active Zone Minutes uses your resting heart rate to gauge exercise effort and gives you a buzz when you step up the intensity so you can make the most of your workouts Better track heart rate 24/7 with PurePulse 2.0, Fitbit?s enhanced heart rate technology Use your voice with Amazon Alexa Built-in to check the weather, set reminders, control smart home appliances and more from your watch Track your time in light, deep and REM sleep, then receive your Sleep Score to better understand your sleep quality each night 6 Months Warranty