BEEPER MODES: There are 2 Beeper modes: Run/Point and Point-Only, which gives you the ability to keep track of your dog. The beeper sound is audible for 400 meters, which lets you train at a distance and still easily locate where your dog is. This collar is a great choice for hunters looking to train their dogs in the field. DESIGN: The STB BEEPER COLLAR - Beeper Version offers a unique single-body receiver with a downward facing beeper horn to eliminate the bulkiness and risk of catching on obstacles such as fences when in the field. This collar is perfect for dogs that are 25 lbs. or larger. SENSOR: The STB BEEPER COLLAR - Beeper Version uses a Piezoelectric sensor for the most accurate motion detection for the Beeper Modes. IPX9K WATERPROOF CERTIFIED: The STB BEEPER COLLAR - Beeper Version is IPX9K waterproof certified, which means it passed the International Protection Marking system. Products are verified if they can stand a close-range high-pressure liquid spray from 4 angles (pressure of 80-100 bars and a temperature of 176°F). RECHARGEABLE BATTERIES: The STB BEEPER COLLAR - Beeper Version has rechargeable lithium polymer batteries that can be rapidly charged in two hours.