fitbit versa smart watch, black/black aluminium, one size (s & l bands included) (renewed) fitbit track your all day activity, 24/7 heart rate, & sleep stages, all with a 4 plus day battery life (varies with use and other factors) and a slim, comfortable design with a lightweight, anodized aluminum watch body. syncs with mac os x 10.6 and up, iphone 4s and later, ipad 3 gen. and later, android 5.0 and later and windows 10 devices. syncing range: up to 6.1 meters use 15 plus exercise modes like run or swim (fitbit versa is water resistant to 50 meters) to record workouts and connect to smartphone gps for more precise real time pace & distance access your favorite apps for sports, weather & more and get call, calendar, text, and app alerts get call, text, calendar and smartphone app notifications when your phone is nearby. plus send quick replies on android only automatically track select sports & workouts with smart-track and use female health tracking in the fitbit app to log periods, symptoms and more operating temperature: 10° to 60° c