Rest easy knowing this HD Super Duty mattress will perform soundly, night after night. This collection integrates an advanced support system with comfort layers that will mold to the shape of your body. The silk, wool, and cashmere blend regulate temperature and wick away moisture. Heavy duty spring design provides the strongest support system to ensure support across the surface for proper spine alignment. The Oliver contains 1,070 of these steel springs for firmer, deep-down support and comfort throughout the entire mattress. A consistent sleep surface is provided with a steel encasement that reduces the roll-off feeling and moves easier for adjustable bases. Rest assured of the quality of this mattress with the twenty year limited warranty.