A very small magnesium block with glued-on sparking rod and similar size steel sparker, fits in a tiny woven nylon cordura pouch and is attached to my key ring. A unique item I found in a US outdoor store and is far from the only emergency firestarter I carry- for instance I also have a split pea lighter on the same ring- but it requires no fuel and is always with me as a third level backup. I think everyone should have one, but I've only seen the forgotten company's fairly nifty products that one time.