Polar A300 Fitness Tracker and Activity Monitor with Heart Rate Monitor Black (Certified Refurbished) The new A300 combines the best of the smart heart rate training features you have come to expect from Polar along wtih daily activity and sleep tracking to give one a complete view of their day. Customize your A300 to fit your style with changeable wrist bands in vivid colors (additional colors sold separately) Certified Refurbished by POLAR, units include Brand New Wristband and Brand New Battery" Motivating feedback right after exercise. Polar H7 required. Gives clear guidance on how to get into shape faster. Polar H7 required. Lets you know exactly how many calories youve burned. Gives feedback on your daily, weekly and monthly activity, showing how your active choices help you stay healthy.