Esbit solid fuel tablets are an excellent item. It is a stable, non-explosive and non-toxic fuel. They work at high altitudes and sub-zero temperatures with no visible smoke formation. Lights easily with matches, burns cleanly without residue and doesn't spark or smoke. 5 minute burn time per cube (approximate). These fuel tablets make an excellent fire starter as well! Comes in a pack of 20 tablets, about 4 g each.