Marc Jacobs Riley hybrid smartwatch automatically tracks and monitors sleep and activity, lets you filter which notifications you receive and allows you to control your smartphone's music with the push of a button. Powered by a coin cell battery, this watch never needs charging. It is compatible with both Apple and Android devices. This hybrid smartwatch features a blue rubber strap and 44mm blue aluminum case. Activity Tracker: Yes, Battery Life: Up to 6 months Based on usage, Case Material: Aluminum, Compatibility: Android OS 4.3+ or iPhone 4s/iOS 7+, Connectivity: Bluetooth Smart Enabled / 4.1 Low Energy, Heart Rate: No, Sleep Monitor: Yes, Interchangeable: No, Notifications: Yes, Strap Material: Rubber, Touchscreen: No