Fortress Survival Stove Unique Feed Ramp - Makes it easy to stack longer pieces of fuel making the burn process more controlled and efficient Bio-Fuel Powered - The most widely available fuel source in the world so you will never be without fuel to burn Compact Design - The Interlocking pieces break down into a 3.5W x 6L x 1/4"H Flat footprint which takes up very little space in your bag and weights under a pound Rocket Stove Design - Creates a strong stream of air that flows upward like a chimney for maximum heat transfer Super Efficient - Only the tips of the fuel wood are burned, eliminating that wasted fuel and limiting smoke