A system conveys two gases separately until controlled delivery and gas mixing are desired. The device maintains separation between the two gases with sealed, high temperature materials, and a geometry that contains gas flow channels that do not allow gas mixing. The present design provides a seal at the interfaces between components. An outer ring and an inner spool are assembled together to form a single component that accommodates the input of two, initially separate gases, and then contains and conveys the two gases separately to an exit surface where outlet holes allow the two gases to mix and react in a controlled manner upon exiting the component. The inlet holes for both gases are located on one side of the spool. The exit holes are formed in a centralized, alternating, completely interspersed array or grid-like pattern on the opposite surface of the spool.