A bottle rocket is a very small skyrocket. A typical bottle rocket consists of a rocket engine attached to a stabilizing stick. The user can place the stick in an empty bottle (hence the name), and ignite the rocket engine; the mouth of the bottle guides the stick, stabilizing the rocket in its first moments of flight.
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 a motor about two 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 gross. _Wikipedia