The video shows a man making "earth cannons" to participate in the annual firecracker contest held in the northern provinces of Vietnam. (on July 5)

"Earth cannon" also known as firecrackers, firecrackers is a Vietnamese folk game that uses a type of firecracker made of earth.

Tools for playing earth cannons are made from highly viscous soils such as clay, clay, etc. Firecrackers are usually shaped like a pan without a handle or an oval with thicker walls than the bottom with flexible dimensions.

At contest festivals, earth cannons are made very large, called firecrackers and can be used from 20 kg to 50 kg of earth. The playing field is usually a flat surface as possible so that the rim of the cannon can make close contact to cause a loud explosion. Soil is used to mold firecrackers many times so the ground is cleaned of dust so that the dust does not dry the soil.

In the Northern Delta, a number of localities hold a land firecracker contest. The earth cannon is very large, usually weighs 20–50 kg, has a rim and has to be carried by many people when the firecracker explodes. In addition to the loud bang, the winning land firecracker must also meet a number of other requirements such as the hole, the position of the rim after the explosion... The most traditional and oldest festival is in the areas of Ninh Giang, Hai Duong, Vietnam.