Ski Rescue Sled Kits
Unless you are leading a back country tour, it is unlikely you are carrying a full evacuation kit in your pack. Any home made device typically renders both your poles and potentially your shovel unusable for any further evacuation needs. In addition, most home made devices take a significant amount of time to construct, typically with small parts that can get lost in the snow, all of which take time.... which may not be a luxury you can afford.
Whether you need to get out of the elements, or down to a place where a rescue team can reach you by helicopter, or even to reach a signal on your cell phone, the Snap Evac gives you and your companion a way to get out of danger and get to help quicker.