I just got a Sport Dog Teck GPS tracking system. This is the gps tracking only. It does not have maps like the Garmin Astro but it does give quick gps location of your dog. It is easy to use, and i have had no problem so far. I makes finding you dog in the field very easy. I paid $449.00 at Scheels Sporting Goods. The collar is just a little big for the neck of my dog. I have a 13 inch 1 year old male that weighs 20 lbs. I have it tightened down to the last hole, and it is a little loose. The second day of using it my dog had no problems with it on his neck and he ran like it was not on his neck. I had to trim excess collar strap off or it would get in the way.