Basic regulations for checked baggage on international flights: 1. It is prohibited to carry any intimidating instruments, such as firearms, military or police equipment, and controlled knives; 2. It is prohibited to carry flammable and explosive items, such as lighters, firecrackers, fireworks, and alcohol; 3. Other prohibited items explicitly stipulated by the state, such as narcotics. For more detailed regulations for checked baggage on international flights, please refer to https://en.ch.com/flights/excess-baggage