https://www.cantamedical.com/products/20l-oxygen-concentrator/ 20 LPM Oxygen Concentrator 20L atmospheric pressure: The original intention of CANTA to design this machine was to make the machine exert more energy. HG20L not only allows multiple people to inhale oxygen at the same time. The customized HG20L can supply oxygen indoors like an air conditioner. Main Features of 20L Oxygen Concentrator The CANTA Medical brand oxygen concentrator 20 lpm provides oxygen with a concentration of ≥90%.All Rights Reserved