Polar A370 is a sleek fitness tracker with continuous wrist-based heart rate. Tracks daily steps, distance and calories burned. Polar Sleep Plus; analysis follows sleeping patterns and provides feedback. Use your phones GPS to track speed & distance. 24/7 companion with continuous heart rate tracking and a detailed overview of your daily activity. Polar sleep plus tracks your sleep and gives you valuable sleep insights. Features Heart rate monitor. Manufacturers 2 year guarantee.