Fitbit Versa 2 Health & Fitness Tracker Smartwatch FB507BKBK 。Experience Versa 2. Versa 2 tracks all-day calorie burn and real-time heart rate zones to give you meaningful insights into your fitness & wellness. Waterproof. Lightweight. Battery lasts 6+ days. The thing that sets it apart from other fitness trackers is its built-in Amazon Alexa, which makes it possible to check the weather, set alarms and timers, control other smart devices and check up on headlines with the sound of your voice. It also has nice smartwatch-like qualities, such as the ability to download Fitbit-compatible apps like Strava, Spotify and Starbucks and use them on a large, easy-to-see touchscreen watch face.