Smart watches powered by the Wear OS by Google work with iPhone and Android Phones. Case size: 44mm; Band size: 22mm; interchangeable with all Fossil 22mm bands Battery: 24 HR + multi day extended mode **Varies based on usage and after updates install**. USB cable with magnetic charger snaps two rings on watch case back and spins 360 degrees for ease of use. Charge up to 80% in under an hour Health and fitness: Heart Rate & Activity Tracking using Google Fit; Built-in GPS for distance tracking; Swimproof design 3ATM; New wellness enhancements allow you to track sleep history, monitor your restfulness and set sleep goals Lifestyle: This smart watch has always on display with thousands of watch faces to personalize your look and always see the time. Hundreds of apps from assistant to fitness, payments, music, social, news, games, stop watches, and more. With a swimproof design and charging in less than an hour, it’s perfect for all your activities. Smart watch functions: Stay connected with notifications for calls, texts, apps and automatic time, time zone and calendar syncing. Never miss a call - answer and make calls directly on your watch when your phone is out of reach.