Runs on BATTERY. Perfect Holiday gift 🎁 Track your steps, sleep and daily activities in style with this charming activity tracker available in other colors on my page! Light notifications keep you updated on your progress, while a connected app lets you customize your experience. The Bluetooth®-enabled design can even control your camera and music for added convenience. * 26mm case * Double stud closure * Compatible with Android OS 4.4+ and iPhone iOS 8.2+. NO CHARGING.