Garmin Astro 430 Expanded dog capability - track up to 20 dogs from a range of up to 9 miles GPS/glonass - high-sensitivity GPS and glonass satellite reception has the ability to track in more challenging environments than GPS alone Preloaded mapping - includes preloaded topo U.S. 100K mapping and a free 1-year birdseye satellite imagery subscription Hunt metrics - hunt metrics dog performance data shows distance traveled, time afield and more, so you can train your dog more effectively Optional battery - optional in-unit rechargeable nimh battery Pack or uses standard AA battery power. Water rating: IPX7