Howdy Elksniper,
Thanks for your interest.
Decided to post on the forum as there' s bound to be others interested.
The E-Perb is a Locator Beacon, that works off satelites.
It is on the same frequency as the locator beacons that are on board commercial aircraft.
They are monitored world-wide by various authorities, and are generally 100% reliable.
In NZ the monitoring is done over in Australia i.e. A Different Country and 10,000 KM away. When they pick up a signal in our region they notify our search and Rescue people in NZ.
To accurately locate the beacon they have to go and search with a helicoptor mounted search device, which can pin it down to about 20 metres.
The Satelite receiving station can only give an estimate of position.
You can get some models that have an encrypted signal which individually identifys the beacons. i.e. If you set one off they can tell that it is your beacon. So with a bit of luck someone knows roughly where you are and can come out looking.However most can not be individually identified.
There' s heavy penalties for setting one off without cause.

I have only ever once set one off. It was about a year ago (New Years Day 2002.) I injured my leg, not severely, just ripped the calf muscle. However I was on my own, and stuck in some very remote mountainous terrain. And the weather had turned real bad, with rivers rising big time. I had no choice but to set it off. As I couldn' t walk or bear weight, let alone carry my pack out through flooded rivers.
I was real glad to get evacuated by chopper.
We use them a lot if we' re hunting alone or in real remote areas.
They are not expensive to buy, about USD$200 or down here we can rent them for USD$10 a week.
I prefer to rent, as that way you get a fully serviced device.
The beacon weighs about 1/2 a pound, is waterproof and straps around your waist, or on your belt.
I reckon they are brilliant.