Choosing an oxygen concentrator is recommended to first confirm how many liters you need to buy to see if it is applicable. Such as 3 liters of oxygen generator, that is, under the premise of maintaining 90% oxygen concentration, the maximum flow rate can reach 3 liters, if it is said to be more than 3 liters of flow rate operation, then its blowing out of the gas oxygen flow rate will certainly not be able to meet the 90% oxygen concentration. Therefore, the higher the specification of the number of liters, indicating that the machine's oxygen production function is stronger, 5 liters of oxygen concentrator means that the machine can be in 90% oxygen concentration under the amount of oxygen for 5 liters of oxygen. Small oxygen concentrator in Guangzhou also have to buy, the provincial Chinese medicine diagonally opposite Philips store, you can first go to understand.