The unit is very compact and well thought out. From the ACR Website (http://www.406link.com/406Plus.html):
From the Equipped to Survive Website, (http://www.equipped.org/blog/?p=284):What about those times you just want to check in and let someone back home know that you're okay? With 406Link.com, you can let friends and family know everything is fine with a pre-programmed message. With a push of the self-test button on your 406 MHz beacon, a message is sent via email or text to up to 5 predetermined contacts. (Just think of it as the "Honey, I'm OK" button.)
With 406Link Plus, you get all of the testing power of the basic 406Link plan, PLUS the added features of multiple SMS and email messaging (up to 5 contacts), trip planning, and GPS test location. Newer, GPS-enabled PLBs will also allow you to send "I'm Ok, I'm here" messages with a hyperlink map of your GPS location.
Price tag, about $250.00 (or thereabouts).The ResQLink uses a 66-channel GPS for very quick acquisition of location, like its previous generation brethren that had very quick time to first fix, and has a full GPS self-test, which I prefer. It can also be used with ACR’s 406Link.com subscription-based web site for through system testing and limited messaging with GPS location. Two days of free testing are included so that the new owner can assure themselves that the PLB is working by testing it up to the COSPAS-SARSAT geostationary satellites and back down to an earth station.
ACR claims that the ResQLink will always exceed 5 watts output, which they claim to be better than the McMurdo’s measured nominal 4.6 watts. They are claiming typical battery life of 30-40 hours at -4 degrees F (-20 C), considerably more than the minimum 24 hours requirement.