The Fitbit Alta Black Activity Tracker is a sleek and functional device designed to track your all-day activity and sleep quality. It provides accurate measurements of time and allows you to set fitness goals. The Alta model comes in a stylish black color and is made of durable plastic. It is compatible with various operating systems including Windows, iOS, and Android. With features such as smartphone notifications and interchangeable bands, this activity tracker is perfect for fitness enthusiasts looking to improve their overall health and well-being (missing charger).