The Fitbit Charge 2 Activity Tracker in Plum Purple is a fitness band designed for both indoor and outdoor activities. It measures heart rate and provides measurements in both decimal and imperial systems. Made of plastic, this activity tracker is compatible with Android operating systems and is suitable for unisex adults. With features such as Bluetooth connectivity, alarm function, and calorie monitoring, this Fitbit Charge 2 model is ideal for gym training and running activities.