ECOlite® 4000 is an electronic oxygen gas conserving device, which enables patient friendly and efficient long term oxygen therapy treatment (LTOT). The small, internal regulator, that allows the user to select a supply inlet pressure of between 1,6 to 5 bar The working pressure of the device is regulated to 1,6 bar which enables a both clinically and physiologically patient friendly oxygen administration The device has two operating modes, Automatic and Manual The battery life time of the device is prolonged to last for 200 hours. Standard AA 1,5 volt batteries are in use