FIDO is an innovative globally patented rebreathing system, it is light, compact and easy to transport for advanced care in the field. It only weight 450 grams. FIDO consumes 80 litters of free gas, and with a bottle of 40 centilitres of O2 it will provide 1 hour of treatment. FIDO delivers 52% of O2 and can go up to 89% of O2 if needed. FIDO generates warm return air to the patient, about 33 degrees Celsius and humid air <95%. In comparison; Free-flowing systems consume 1,300 litters of free gas and a bottle of 6.5 litters of O2 for 1hour treatment too. FIDO manages to treat 16 patients on the same amount of 02 as a free-flowing system.