Summary: I am in the mlitary and the use of this GPS was solely in a field environment. I orginally purchased this product when I went to the National Training Center at Fort Irwin, CA. As a tank commander, I used it only when I was dismounted. There is no external antenna attachment so it was obviously useless inside the tank, even with the hatch open. A buddy of mine had a magellan in a Bradley and his worked and my Garmin did not. The next test was in Iraq.
Summary: I have had the misfortune of buying this product, I would not suggest it to ANYONE, you could toss your money out the window and get more of a benefit. The problem is this, Garmin, however may make great GPS hardware, there software ..., Real bad! whn=en you buy a Garmin GPS, you MUST use there software, if you do not, you will not have any information as to where you are. The ...is that there software is VERY expensive, and DOSNT EVEN WORK!