Battery for 6+ days: Track from day to night without stopping for a charge with a 6+ day battery. Gets a full day's charge in just 12 minutes. Pay Hands Free: Pay from your wrist at locations accepting contactless payments. Voice Assistant: Amazon Alexa built-in lets you set alarms, check the weather and more. Sleep and Body Metrics: Get multiple key metrics such as your breathing rates to know your body better. Phone Compatibility: Versa 4 is compatible with most cell phones and tablets running on the latest versions of Android and iOS.