Relefree Ferrocerium Rod Flint Fire Starter lighter Slim Magnesium Camping Survival Tool Kits Black (Pack of 6) 4.5mmx75mm Ferrocerium rod is made from Iron, Magnesium and mostly of an alloy of rare earth metals called mischmetal with an excellent pyrophoric percentage : 98%min. Diameter: 0.18 inch(4.5mm) Length:approx 3inch(75mm) Material: Ferrocerium