3Plus Callie Smartwatch is compatible with Android and iOS operating systems. It connects via Bluetooth with your smartphone. The screen size is 37mm and comes in a round TFT display that looks elegant. It has various features like a pedometer, calories calculation, monitors sleep, mileage, weather forecast, stopwatch, and much more. Access your social media messages and notifications at your wrist. Also, you can manage and receive a hands-free call through this watch. It is durable as the materials of this watch are made of premium quality. The watch comes with a 1-year warranty. It is widely compatible.