Naxa NSW-13 is a fitness tracker watch with a built-in OLED screen that displays time, call notifications, and heart rate. It also tracks steps taken, distance traveled, calories burned, and active time. The watch has a built-in rechargeable battery that lasts up to 80 hours on a single charge. It is compatible with both iOS and Android devices and can be used to receive notifications, set alarms, and control music. The watch is also water-resistant and can be worn while swimming or showering.