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 separately.