15 inch Gel infused memory foam mattress keeps you cool at night and still gives you the support you will need night after night. 4 inches of gel memory foam, 2 inches of our unique design air flow sculpting foam. This is ideal for airflow and support. 9 inch base foam, this support foam will not let you sink in far enough into the mattress. It offers support for your back, shoulders and hips. Easy Zipper design. So you don't need to flip your mattress back and forth to unzip and wash the cover. Simply unzip the side of the mattress, pull the cover off and wash.