LANACare Natural Sleep duvets are filled with organic untreated merino wool. They are extremely light and soft, providing the ultimate comfort. Untreated wool filling is especially healthy and breathable. It will cover you in light warmth and nurture your healthy and natural sleep throughout the night. Highest quality cotton touches super gently to the skin. Summer duvets include a thinner layer wool, therefore more suitable for fresh summer sleep. Standard duvets include ordinary layer of wool, just enough to keep perfect warmth and coziness all year round.