High-Sensitivity GPS-enabled dog tracking system. Pinpoints your dog's position and shows you exactly where he is. Includes newest, upgraded Astro 320 handheld with simplified interface, better reception range, and enhanced mapping along with latest DC-40 Transmitter/Collar. Unit is an upgrade from the 220 and we find more accurate and easier to use. Comes with Handheld, DC-40 wireless transmitter, Extended Range Antenna, Carrying Case, Belt Clip, AC Adapter for DC-40 & manuals.