The Serta Perfect Sleeper Select Carverdale Firm Mattress features Sertas Cool Twist Gel Foam and new 739 Custom Support Firm Individually Wrapped Coil System. It is designed with a unique set of features to help solve 5 common sleep problems. It helps reduce tossing and turning with Cool Twist Gel Foam as well as encourages proper back support and alignment with Sertas new 739 Custom Support Firm Individually Wrapped Coil System. This mattress promotes a balanced sleep temperature with an overall mattress design that helps promote airflow and minimizes impact from partner movement with a premium support system and advanced foams designed for motion isolation. It also resists sagging and edge roll-off with Sertas ComfortLast Construction and Best Edge Foam Encasement. This mattress also features a special innerspring coil gauge design that helps create a firmer feel across the mattress when compared to the Elkins Plush.Dimensions: Twin: 39 W x 75 D Twin XL: 39 W x 80 D Full: 54 W x 75 D Queen: 60 W x 80 D King: 76 W x 80 D Cal King: 72 W x 84 D.Serta Perfect Sleeper Warranty.Comfort Level: 2.