The breathing bag is used for respiratory circulation during anesthesia surgery. It is a respiratory anesthesia system used to store gas components, used to regulate the amount of gas supply, when the gas supply is more than the system requires gas, it will be excess gas temporarily stored, and when the gas supply is insufficient for the system requires gas, it will be released to give the supplement of the stored gas, according to the specifications of the smallest to the largest applicable to infants, children and adult.