The Mi Band is comprised of two components - the band itself and a Bluetooth capsule that tracks your activity. The product has no screen, but its three LED indicators let you know how close you are to achieving your daily step goal at any given point. The capsule can track your sleep patterns, let you unlock your phone without a password when it is nearby, and vibrate to alert you about incoming calls and alarms. It has a smooth metal surface with the three LEDs on top, though the side in contact with your arm is made of plastic.