It is a two-wall design, which preheats air in between the walls to ignite the smoke. Well-tended, this produces a bright, smokeless flame which produces little soot and leaves little to no scorching on the ground below.
It is built from commonly available (in the United States) parts: a quart paint can, a smaller tin can, and a shorter tin can. The only specialized tools are a safety-style can opener and an Irwin Unibit #1, though similar designs can be made with just a church-key and ordinary can opener and alternate tools are discussed in appropriate steps.
The whole thing can be built in about an hour. This model weighs 6.6 oz (187 grams) after several firings, and nests in, e.g., the Snow Peak 900 Ti or Al pot.
Ready? You'll need:
Step 1: Materials
A 19 ounce Progresso soup can. Other cans such as 20 ounce cans of fruit will work as well, but the
Progresso cans are a bit shorter, which we want.
A Large, short can. Mine had bamboo shoots in it; many cat foods and canned meats come in this sort of can. The diameter should be a little larger than the inner ring on top of the quart can. Don't get an aluminum one, it'll melt and buckle in the heat.