The Amazon Halo Band is an activity tracker that comes in a rose gold color and size L. It is powered by batteries and can be used both indoors and outdoors. It is compatible with iOS and Android operating systems and has a battery life of up to 7 days. The band features a heart rate monitor, sleep tracker, and fat monitor. It is also water-resistant and can be used for various sports and activities such as gym training, walking, cycling, swimming, yoga, Pilates, running, and jogging.