Dogtra Pathfinder 2 GPS Dog Tracker & Training Collar The additional PATHFINDER2 GPS Collar for the expandable PATHFINDER2 GPS Dog Tracking and Training System. Features include: LED Locate Light, Pager Vibration, Tone, Nick and Constant E-Collar training functions with a 9-Mile tracking range and is fully waterproof. Users can pair up to 21 dog collars to the PATHFINDER2 system. This GPS dog tracking collar is designed to be paired to the PATHFINDER2 GPS Connector in order to operate. Additional Information: PATHFINDER2 GPS Connector required to operate and is sold seperately. Compatibility: Only PATHFINDER2 Series, PATHFINDER2 App, PATHFINDER2 GPS Connector What's in the box? 1-PATHFINDER2 GPS Add. E-Collar Black 1-USB Charger BC 5V 2500mA Specifications 12"+ Neck Size9-Mile RangeRheostat/Volume Dial with Stimulation Levels 0-1002.5 Hour BatteryNick and Constant StimulationNon-Stimulating Pager VibrationAudible ToneFully Waterproof ReceiverExpandable to 21 Dogs and HuntersGeo-fence OptionOffline MapsPrecise and Up-to-date MapsTracking Only ModeFor Dogs as Small as 35 lbs.