Evoras unique floating seal engages to wrap around the nose providing a flexible, gentle, comfortable seal at the base of the nostrils. The cushion's integrated stability wings work together with a lightweight, flexible breathing tube and 360 degree swivel, to keep the mask in place without tugging or pulling as you shift, roll and move during sleep. Replacement cushion. Quantity in this listing: one single medium cushion. No other parts of the mask are included.