In answer to LifeLONGBackCountrySkier's review below, what's he's writing as fact is simply wrong. I'd hate to see someone buy a less capable beacon based on patently wrong information.

1. The DSP is fully backwards compatible with all beacons which operate on the standard 457mhz frequency. It will pick up even the oldest analog beacon. In fact, old beacons tend to drift of frequency when cold (Google it), and the DSP is one of the best at finding out of frequency beacons.

2. Andrew is endorsing it with HIS LIFE. Seems pretty solid to me.

3. When worn correctly, with the LCD facing the body, the body of the avalanche beacon shields the switch for anything except a very large magnet. Several beacons use magnet switches since they're durable and completely waterproof, and this is not a new allegation, but it not something which happens in the field when properly used. Beyond that, many beacons have issues with radio, iPods, or cell phones near them (particularly the Ortovox S1) due to how sensitive the receivers on them are, so you should NEVER carry any electronic equipment near your beacon to begin with.

4. This is simply wrong. The DSP has consistently turned in the highest marks in field test both in range and ease of use. In fact, it's speed and ease of use are it's hallmarks. Don't take my word for it though, go to http://beaconreviews.com or http://www.wildsnow.com and educate yourself.

Although it claims to be a three antenna digital beacon, it seems Ortovox has stripped the best parts of the technology out. First, it switches to fully digital much too late, when you're already within 15m. It would speed up the search greatly if the directional arrows activated as soon as possible to vector directly to the buried beacon. Second, the third antenna is supposed to allow the beacon to resolve spikes, which can make it appear buried beacon is up to two meters away. However, the Patroller was completely unable to resolve spikes. For the money, I think the proven Tracker DTS is a much better choice.

These beacons were really solid starting with the 5.0 firmware update, and between the flagging and scanning functions can handle multiple burials very well. The three antenna design resolves spikes without any issue. It's very simple to use, and I like to think of it as the three antenna version of the tracker for it's simplicity and easy of use. The new carrying pouch it comes with is the most comfortable one I've ever used, but it can be hard to get out until the fabric stretches out a bit from use. The range is exception for a digital beacon, and its handling of worst case orientation of the transmitting beacon is the best out there. Like with any beacon regular practice is a must, but this is the beacon I currently use.

Quickly simply, there is no reason to buy a M2 at this price. For less money you can buy the BCA Tracker DTS which is a two antenna digital beacon. While it doesn't have the range of the M2, you'll more than make up the fine in the intermediate search as the directional arrows vector you right to the beacon. There is a reason virtually everyone who travels into the back country regularly has switch over to, at a minimum, a two antenna digital beacon. Bottom line, if you're about to drop the cash on this, go buy the Tracker instead, and you'll find your friend faster.

This beacon is inexpensive and transmits like any other beacon. However, it's search range is very meager and you need to be well practiced with a single antenna beacon. If you're going to be in any situation where you might need to search for someone else, DO NOT BUY THIS. At a minimum, drop the cash on a BCA Tracker DTS.