This replacement cushion is designed for use with all SleepWeaver Elan Soft Cloth & Masks. The Elan's cloth cushion inflates like a balloon during therapy pressing gently againts the face to create a soft, leak free seal with no pressure points. Because SleepWeaver cloth is breathable the mask feels cool and dry to wear and the fabric feels natural on the skin unlike the plastic and silicone of most CPAP mask solutions. SleepWeaver Elan cushions are available in three sizes -- Small, Regular and Large. To determine the size you are currently using check the bottom of the cushion and you should see a printed label. Any size cushion can be used with any size SleepWeaver Elan mask.