EXTRA-LARGE COMFORT: The extra-large size of the TravelMate Memory Foam Seat Cushion means that pressure is spread over a larger area, giving you a more comfortable fit. Each premium memory foam cushion is 19" x 17" x 3" to fit a variety of seats. BREATHABLE MEMORY FOAM: Our extra-large cushion is covered with a layer of 3D ventilated fabric to disperse heat over a thick layer of premium memory foam, so you won't experience heat buildup even after hours of sitting. WON'T FLATTEN OUT: Give the TravelMate Extra-Large about a week to conform to your shape, and you'll experience custom-fitting comfort every time you sit on it without the eventual flattening effects of inferior memory foam cushions.