The loudest double-bang gun is what everyone often says. Firecrackers with two kicks are a traditional folk product, which is often used in festivals, weddings, commemorative ceremonies and many other occasions. It is based on the principle that the powder at the bottom is lifted off by the reaction force generated when it hits the ground when it explodes. The paper tube with double kicking firecrackers is divided into two layers, and the function of the lower layer is to send firecrackers to the sky. After the upper layer lifts off 10 ~ 20 meters, it will explode in the air.