The Serene Sky plush hybrid mattress offers Serta’s renowned comfort at an unbeatable value. It features layers of PillowSoft foam, PillowSoft Aire, and Cool Twist Gel Foam above a pocketed coil support system for cool, comfortable support night after night. The Cool Twist Gel Foam is designed to promote airflow and heat dissipation to keep you comfortable. Enjoy low motion transfer that helps you remain asleep throughout the night. This mattress is CertiPUR-US certified, hypoallergenic, and compatible with adjustable bases.