However, there is software that is supposed to be available from Horus or Kestrel (Nelsen-Kellerman) that is not available.
Contacting Kestrel yields them to tell you to call Horus Vision, and Horus Vision will completely ignore you (even when you start out VERY polite).
Kestrel also does not have current software to support Windows 7, so if you plan on hooking up you device to a laptop for programming or reading data in the field, forget about it.
Horus Vision is supposed to have a software for the 4500NV ATRAG with Blue Tooth (and I assume serial coms), but this "Gun Library" software does not exist [though it's listed in the manual for the unit].
Basically, I would consider avoiding this product if you plan on using it for more than 5 gun and/or proprogrammed batches of ammo. (I chrono all batches of ammo... So using 5 buttons on the 4500NV isn't really helpful.)
According to the documention, the Gun Library software is supposed to support MORE than 5 guns... (50)
A disappointing purchase for the intended use to be sure.
(What worse is that I was looking at this for a third party that was going to purchase about a hundred or so [extra $$$ in the budget that needed to be used], and they poopoo'ed that idea the moment we couldn't get support... and you should NEVER need to use a DoD or LE affiliation to get a response!)
If you are hunting, buy one without BT and save the cash.
As a Taxidermist I look at hundreds of Whitetail Bucks every year. I know that I have seen many different ways people judge the size of racks on live deer. I think for the most part they all are pretty close. I'm going to give you some measurements that I have noticed being right on in just about every deer. We have used it in the last couple years and have only been off by about 5-6 inches. We do study the deer while bowhunting so we get a little more time to look at them....