For emergency artificial respiration. This device is ideal for administering either pure oxygen or room air to oxygen deprived patients. Special valve allows lung inflation upon compression of bag and passive exhalation of CO2 while fresh air refills up the compressor bag. Two options include your choice of hooking up to a central oxygen source or detaching and using room air. Attachment will fit standard endotracheal tube or can be used with an airtight mask. 2-liter.