TRANSMITTER COLLAR FOR THE ASTRO(R) DOG TRACKING SYSTEM; GPS RECEIVER & VHF TRANSMITTER ON COLLAR; WEIGHTED COLLAR KEEPS TRANSMITTER UNIT UNDER DOG?S NECK WHILE FLEXIBLE GPS ANTENNA STAYS POINTED TOWARD THE SKY FOR OPTIMAL PERFORMANCE; DOG POSITION UPDATES EVERY 5\, 10 OR 30 SEC; 7-MILE RANGE\, DEPENDING ON TERRAIN; RUGGED\, ALL-WEATHER DESIGN-BUILT TO TAKE THE ABUSE OF THE MOST CHALLENGING HUNTS; IPX7 WATERPROOF DESIGN; 17 - 36 HOURS BATTERY LIFE; USER-SERVICEABLE\, RECHARGEABLE LI-ION BATTERY; COMPATIBLE WITH ASTRO(R) 220 SERIES