Sthira is our firmest orthopedic mattress, designed for those who need maximum structural support to correct chronic posture issues. It combines a dense 4-inch Century 90 to 95 density rebonded base with a 2-inch layer of pure GOLS-certified organic Kerala latex. The ultra-high-density foam block prevents any structural deflection, keeping your spine in perfect neutral alignment throughout the night. The thin latex top layer adds just enough gentle cushioning to prevent aching on hips and shoulders — a common complaint with ultra-firm mattresses. This configuration is ideal for stomach sleepe…