Polar CS100b Cycling Computer Simple, straightforward, and intuitive bicycle computer is designed for cycling enthusiasts interested in tracking the basics Measures current, average, and maximum speed, and can estimate time of arrival based on cycling speed; water resistant Automatic/manual target zone, backlight, dome button with touch response and sound, double antenna for longer range and less disturbance, and easy start setting wizard Heart rate displayed as % of maximum heart rate and bpm; HeartTouch button-free operation of wrist unit, oversized display, sound volume level setting, user-configurable displays, and visual and audible alarm in target zones Includes limited two-year manufacturer's warranty