Devilbiss American generator With a capacity of 5 liters Oxygen flow: adjustable from 0.5 to 5 liters per minute It has an oxygen purity sensor (OSD®): an intelligent and continuous sensing system to monitor the quality and purity of the outgoing oxygen and immediately alert the patient if the concentration falls below the required medical level. Alarm for sudden power outage, low oxygen flow rate, and high or low internal compressor pressure. Sale is permissible.