The replacement Flexi Foam Cushion Insert for FlexiFit HC432 Full Face Mask come as a single insert and is available in small, medium, large, and extra large. The replacement cushion is a perfect match for the HC432 Full Face CPAP Mask. By utilizing a hybrid foam cushionl, you'll enjoy the leak free comfort you're looking for—the perfect balance for your nightly therapy. What's Included: 1 Flexi Foam Cushion General Tips Section Where do I find the size? To find the size of the foam insert, pull the insert out of the cushion. Hold the insert as if preparing to place the insert inside of the cushion. A small, embossed letter is recorded at the peak of the insert, where the nose connects to the foam material. Frame and Cushion Compatibility The HC432 foam insert and silicone cushion will not fit the HC431 frame. The HC431 silicone cushions made after April 2006 will fit the HC432 frame. The HC431 silicone cushions made before April 2006 will not fit the 432 frame. The Flexifit HC432 mask size runs a bit smaller than the Flexifit HC431. The manufacturer has stamped the part number (431 or 432) identifying the mask on the upright bar for the forehead support. The manufacturer did not include the alpha characters "HC" in front of the numeric characters. The manufacturer has stamped the part number (431 or 432) identifying the mask on the upright bar for the forehead support. The manufacturer did not include the alpha characters "HC" in front of the numeric characters. 400HC119, 400HC007, 400HC115, 400HC006, 400HC114, 400HC005, 400HC113, 400HC004