VelocityTrack™ technology provides instant visual feedback on the motion of moving radar targets in relation to your boat. This powerful add-on offers yet another way for Halo™ radar to improve your situational awareness and reduce your risk of collision. Using the Doppler effect, the VelocityTrack™ feature is able to detect motion on the first radar sweep for a useful view straight from standby. This feature is available for any new or existing Halo™ radar system via the purchase of a one-time unlock code. Radar system requires a heading sensor with 10 Hz output or greater. This needs to be connected to the RI12