Invacare Perfecto2 V Five Liter Oxygen Concentrator is designed for indoor individual use. This 5-Liter Oxygen Concentrator is intended to provide supplemental oxygen to patients with respiratory disorders, by separating nitrogen from room air, by way of a molecular sieve. It is small, quiet, lightweight and comes standard with the Invacare SensO2 Oxygen Sensor. Perfecto2 provides high concentration of oxygen directly through a nasal cannula. The patient-accessible reset button helps minimize emergency service calls. It is a reliable concentrator with battery-free power loss alarm.