7.5 oz / 213 g with batteries
2.4 in x 6.1 in x 1.3 in / 6.1 cm x 15.5 cm x 3.3 cm
1.43 in x 2.15 in / 3.6 cm x 5.5 cm, 2.6 in diag / 6.6 cm
Here's what other sites are saying:
The Astro 220 GPS 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. The Astro 220 can be combined with DC 20 and DC 30 collars to track your dogs. Rugged quad helix antenna, GPS antenna, and flexible VHF antenna. MicroSD slot lets you add Garmin topo maps for info on contours, lakes, and backwoods. Tracks up to 10 dogs simultaneously. Attach the optional DC 30 to your dog, and turn him loose; no other setup required. As often as every 5 sec., 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. Switch over to the Dog Tracker page to view a compass pointing to your dog's location as well as his current status: whether he's running, sitting, on point, or treeing quarry. Can sound an alarm to let you know instantly when your dog goes on point. Astro boasts a high-sensitivity GPS receiver that can track your dog's position, even in the densest cover. Tracks at a distance of up to seven miles away (depending on terrain). Other features include automatic routing (turn by turn on roads), hunt/fish calendar, sun/moon information, and area calculation. Package includes Astro 220 handheld, carrying case, MapSource Trip & Waypoint Manager CD, USB cable , wrist strap, belt clip, owner's manual, and quick-start manual. This model does not include dog-tracking collars. This model does not include dog tracking collars.
Keep your canine companion found with the Garmin Astro GPS-based dog tracking system, and leave the bushwhacking to your dog! Bundle includes full-featured Astro 220 GPS unit and the DC 30 dog-collar transmitter for relaying dog's position to you every 5, 10 or 30 seconds. Intuitive setup can be readied for tracking in minutes, keeping user apprised of up to 10 dogs' positions (additional DC 30 transmitters not included). DC 30 transmitter collar is weighted to maintain position of transmitter above dog's back. Flexible antenna on DC 30 withstands rugged use in brush. Up to 7 mi. line-of-sight range, depending on terrain. DC 30 transmitter offers 17 to 36 hours (based on position pinpointing frequency) on rechargeable lithium ion battery pack; includes AC wall adapter and DC vehicle charger. Astro 220 GPS offers full mapping abilities with optional map software and is compatible with data cards via the microSD™ card slot. Features barometric altimeter sensor and electronic compass for accurately tracking pressure changes, altitude and direction. Scratch-resistant lens protects sunlight-readable 2.6 in. color TFT display with backlight and rocker keypad navigation. Arrive easily at your destination with automatic routing and turn-by-turn directions. Flexible antenna tracks up to 10 DC 30 transmitters; dog tracker page indicates dog's position relative to the Astro 220. Dog map page shows not only where each dog is every 5, 10 or 30 seconds but also shows a route of the ground covered by each dog. Dog page can also indicate whether your dog is running, sitting, on point, or treeing quarry from sensor information inside DC 30 transmitter. Covey Counter™ waypoints store additional data about the covey including how many birds were flushed and how many were taken. Hunt and fish time page displays good and best time ranges for your current location.
Garmin Astro 430
Garmin Astro 320 GPS
DeLorme inReach Explorer Handheld GPS Receiver / Locator Beacon
$349 - $379
Garmin eTrex 10
Garmin Oregon 600
Garmin Foretrex 401
$180 - $199
Garmin eTrex 20x
Garmin GPS 64