Discount for The Astro GPS Dog Tracker from Garmin is a high sensitivity GPS-enabled dog tracking system for hunters and sportsmen. Pinpoints your dog's position and shows you exactly where he is, even when you can't see or hear him. Includes a bright color-screen handheld GPS device and the rugged, all-weather DC 30 collar; Collar has an integrated GPS transmitter and is specially weighted so the antenna will always point to the sky for optimum signal; Just take Astro outdoors and turn on the handheld and transmitter to acquire GPS satellite signals; Attach the DC 30 to your dog, and turn him loose no other setup required; As often as every five seconds, your dog's DC 30 transmits his position to your handheld, and you can see his current location and a trail of where he's been on the Map page of your handheld.