The replacement SoftSeal Cushion for Oracle HC452 come as a single cushion in your desired size: small or large. Both sizes fit on the Oracle HC452.
Where do I find the size?
To find the size of the softseal cushion, remove the cushion from the mask frame. Hold the two silicone flaps, so the top of the two small openings is facing the user. With the small openings facing inward, the correct direction can be determined by the words "S M A L L" and "L A R G E." If either of these words appear embossed into the silicone above the small openings, then the user has located the size of the cushion. If the words are not visible, turn the cushion 180 degrees to view the other side.