These rockets have been made at least since the early decades of the 20th century, and in many countries, including Japan, China, and Macao. The older type of bottle rocket was typically a black powder skyrocket with an engine about 2 inches (5 cm) long and up to 0.375 inch (9 mm) diameter, mounted on a thin bamboo splint and often having a small report charge. Modern bottle rockets are small and very cheap. They are often sold by the box (but more commonly by the pack, or by the gross, a packet of 144 rockets) for less than $US 0.20 each.