Offering the body cradling comfort of a premium pillowtop mattress with a luxuriously supportive firm feel, the Beautyrest Black Katrina is the perfect match for anyone who wants to benefit from advanced foam materials without an excessively soft feel. Starting with the Advanced Pocketed Coil System, this firm mattress delivers individualized back support and targeted pressure point relief. Directly above the innerspring system is a layer of Micro Diamond Memory Foam, an exclusive material which utilizes the properties of diamond particles to move heat away from the body. And creating the Katrina's exclusive body-conforming, firm feel is a layer of AirCool Gel Memory Foam sandwiched between two layers of Comfort Foam for superior pressure point relief and body-conforming comfort with a cool, refreshing feel. 10 Year Warranty.