The Garmin Astro 220 DC 30 Bundle GPS Dog Tracking System ($599.95 at Amazon.com, Sears, and REI) is designed for hunters and sportsmen but it also works for adventurers who run or
Garmin Astro 430 Handheld Only
Micro-Trak Astro II GPS Speed Sensor W/ 4-Pin AMP Connector - Ag Express