The Fitbit Inspire 3 Activity Tracker in black is a brand new, unopened device that offers a range of features for fitness tracking. With a battery life of more than 7 days and compatibility with iOS and Android operating systems, this activity tracker provides measurements for heart rate, time, calories, and distance. It is designed for both indoor and outdoor use, and includes features such as wireless connectivity, GPS tracking, water resistance, and a variety of monitoring tools like a calorie monitor and sleep tracker. The sleek design and durable materials make this activity tracker a versatile and reliable tool for fitness enthusiasts.