The O-Two Equinox Advantage oxygen/nitrous oxide mixing and delivery system consists of a dual gas (oxygen and nitrous oxide) control module mixing system that maintains the output gas mixture at a constant ratio, over eight settings, from 25% to 100% oxygen. It allows the user to control the mix of gas and oxygen a patient is receiving in order to provide the appropriate dose for the patient and the procedure. Designed for use everywhere from the pre-hospital (ambulance), in-hospital (ER, labor and delivery, etc.) and dental (surgical procedures), the portable system is easy to use and eliminates the risk of delivering a hypoxic mixture.