Amazon.com: Fitbit Versa Smart Watch, Black/Black Aluminium 。The Fitbit Versa — a product it calls a “smartwatch for all.” Fitbit Versa smartwatch, black/black aluminum, one size (s & l bands included) Brand Fitbit Colour Black Special feature Distance Tracker, Calendaring, GPS, Notifications, Heart Rate Monitor Compatible devices Smartphone Screen size 1.34 Inches Age range (description) Adult Easily fit in workouts with personalized on-screen workouts that play on your wrist and coach you through each move Take your favorite music anywhere by storing 300+ songs or downloading playlists from Pandora. Maximum operating altitude - 28,000 feet Access your favorite apps for sports, weather & more and see notifications for calls, calendar events or texts & send quick replies (coming soon to Android) Track heart rate all day, during workouts & over time with a 4+ day battery life (varies with use and other factors). Care- If the band gets wet or if you sweat in it, remove and completely dry it before putting it back on. Give your wrist a rest by taking the band off every now and then Use 15+ exercise modes like Run or Swim (Fitbit Versa is water-resistant to 50 meters) to record workouts and connect to smartphone GPS for real-time pace & distance on screen The minimum and maximum circumference range between 140 - 206 millimeters Operating temperature: -10° to 60° C