Bear's Trundle mattress is the perfect addition to your trundle bed; even your guests will have better sleep. The top comfort layer is made of a Cooling Gel Memory Foam to help draw away unwanted body heat while offering a comfy, contouring hug. High-Density Support Foam provides long-lasting durability and supports growing sleepers as they age up. The cover is a soft, breathable hypoallergenic knit fabric that helps ensure a sweat-free night's sleep. We take sleep quality very serious. So the foams in our mattresses are CertiPur-US certified be made without ozone depleters, chemical sprays, without mercury, lead, and other toxic materials.