The odds of surviving an avalanche are greatly improved if you're found in the first fifteen minutes. So $100 seems like a worthwhile investment for this emergency inflatable marker that's going to make it easier for rescuers to locate you.
If you spend a lot of time on dangerous slopes, expensive inflatable vests or backpacks are probably a wise investment since they'll actually prevent you from being buried alive in an avalanche. But even as just a backup, the cellphone-sized Rotauf MRK5 seems like a no-brainer addition to your kit.
Before heading out you strap the 1/3 pound package to your arm, and pop out the emergency handle. While you don't have much time when an avalanche is approaching, yanking the handle instantly inflates a five liter orange balloon which stays on the surface of the snow because of its lighter density. In other words, it floats. The long rope which keeps it tethered to the victim literally becomes a life line, allowing rescue crews to spend more time digging someone out than hunting for their location. [Rotauf via Gizmag]