Serta's Serene Sky 11"" Plush Mattress offers an unbeatable value from a trusted name. Exceptionally soft, this mattress is ideal for side sleepers who enjoy a cushioned feel. Cool Twist Gel Foam works to create a cool sleep surface which is essential for a more restorative sleep while the 805 Individually Wrapped Coil System provides contouring cradling support. Finally, BestEdge Foam Encasement ensures that you will not have a sinking feeling at the edge of the mattress.