The Cardiosport G0 15S comes with our new Fabric stretch transmitter that will stretch and move with your body for maximum comfort during exercise. It has a user changeable battery to save you time and money. It's also machine washable and has a snap fix quick release buckle for easy fitting and positioning. There is also a single button for switching heart rate on and off. Making the Go 15S truly easy to use. Other features include: A hands free scan feature showing how long and how hard you have been exercising, Time of day, Hi/Low setting in signal beat increments and back light.