The replacement Cushion for the Eson 2 Nasal CPAP Mask includes one cushion available in three sizes: small, medium, and large. The Eson 2 Nasal CPAP Mask Cushion features RollFit technology, which allows the cushion to maintain its flexibility and secure its seal even throughout multiple sleeping position changes. The cushion is made of silicone and is compatible with the F&P Eson 2 Nasal CPAP Mask with Headgear only. Find all compatible parts listed here on the ESON 2 Nasal Mask Parts page. General Tips Section Where Do I Find the Size? The Eson™ 2 mask frame is one size and accommodates all Eson™ 2 nasal cushions. A size is not located on the mask frame as it offers a universal fit. An indention found at the top of the cushion extends downward and has a clear letter embossed on either side of the silicone. The letter "S" represents a Small, "M" represents a Medium, and "L" represents a Large cushion. Compatibility Tips The Eson™ 2 nasal cushion is not compatible with the original Eson™ nasal mask. Cleaning Tips The manufacturer recommends cleaning the Eson™ 2 nasal cushion every day for no more than 10 minutes at a time. Use lukewarm water and mild soap to thoroughly clean the mask. Then, once all soap residue is gone, place the cushion away from direct sunlight and allow to air dry completely. The Eson™ 2 nasal cushion is replaceable. If you notice tears or damage while cleaning the mask, replace the cushion to restore the mask. 400ESN216,400ESN215,400ESN214