A fire piston is an ancient device used to create embers for starting a fire. It’s usually made out of wood or metal, though in the distant past people even made them from bones. The principle behind it is adiabatic heating, where air is compressed so much and so quickly that it heats up to over 800 degrees, igniting the kindling (usually something that lights easily, like char cloth). What’s great about a fire piston is it’s essentially a lighter that never runs out of fuel and doesn’t easily break.
You can purchase a fire piston online, but if you like DIY projects and/or want to save a little money, you can make your own. In the video below, GoingPrepared explains how to make a fire piston from a Maglite Mini Incandescent Flashlight.