The listing, Polar Fitness Heart Rate Monitor has ended.
Please read the description. This is a Polar F4 Fitness Heart Rate monitor. User manual is included. Will need battery. Adjustable band goes around your upper chest under work out clothes. This shows heart rate, amount of time spent in heart rate zone and CALORIES burned. Until knee surgery I did Body Pump and wore this on each workout. No refunds please, as stated it will need a new battery, but this item sold for over 100 dollars new and is very helpful.