Very simple, the material needs iron sheet (or iron beryllium barrel), thick iron wire or iron bar of about 4 mm, and the iron sheet is rolled into a barrel of about 40cm high. The diameter depends on the situation, generally about 40cm. The upper part is open and the lower part is sealed. The upper part of 10cm is separated by a circular iron sheet with small holes, and the iron sheet is covered with carbon. Open an adjustable window on the barrel wall of 10cm, and then cut off the upper part of 15cm (with barbecue food on it) with an iron bar. Simple cooking.