Enjoy a lavish rest every night with the premier offering in our most advanced collection yet, Beautyrest Black® Hybrid KX-Class firm tight top mattress. This cutting edge mattress offers up to 21% more support where your body needs it the most.* What's more, our new plant-based cooling technology helps provide up to 18% more cooling power to keep you comfortable as you fall asleep and all night long.** This new mattress line also includes comfort, pressure-relieving and support upgrades as well as 2X more memory foam*** compared to Beautyrest Black® Hybrid LX-Class and CX-Class models. The result: our most comfortable mattress ever. A luxurious layer with silk, alpaca and cashmere provides unmatched comfort and breathability while Self-ResponseT Latex ensures individualized support for different parts of your body. Lasty, 2000 micro-coils add an additional layer to our Premier Support System and provide precise conformability for a first-class sleep experience. *in the center-third of mattress, exact percentage varies by model. **vs. Harmony Lux Collection, which cools for the first 20 minutes only. ***by weight.