To be blunt, Iceland is not Disneyland. Things don't always go as planned. A hike can turn disastrous, even for experienced travelers.
Getting stuck on the highlands is no joke. We at Rent a Tent always recommend planning ahead. Plan your route beforehand, let people know where you are going and when you intend to return and most importantly; have the right gear for your trip.
These emergency flairs are only to be used in the most dire circumstances, having one could save your life.
Aim the flair into the sky and fire. The flair burns a bright red for 40sec while floating down in a parachute.
DO NOT USE UNLESS THERE IS AN ACTUAL EMERGENCY.