Oversized matches with an extended chemical head that burns fiercely for around fifteen seconds and relights itself after being submerged. They are not a novelty: they are what works when an ordinary match does not.
The case for carrying them is narrow and real. A disposable lighter fails in three ordinary situations: it is cold, it is wet, or it is empty and you did not notice. Cold is the common one. Butane lighters lose pressure as the temperature drops and simply stop producing a flame long before the fuel is gone, which is exactly the weather in which you most want a hot dinner.
Buy the ones that come with a strike surface in a sealed case, and keep a spare striker separately. The matches being waterproof is of no help if the striker on the box has turned to pulp.
They are a backup rather than a primary. For everyday lighting a long-nosed lighter is easier and cheaper, and these live in the box for the day it does not work.