Fire Liters boast an efficient combustion rate, with a burn duration of up to 12 minutes. Its versatility allows for use with campfires, charcoal grills, wood stoves and fireplaces. Constructed from 100% recycled materials in the USA, Fire Liters are non-toxic, waterproof, smokeless and California-approved. The 36 Lite box is an ideal size for portability and convenient storage.