California King sheets are specially designed bedding items that fit a California King mattress, which measures 72 inches wide by 84 inches long. This size is longer and narrower than a standard King mattress, making it essential to use sheets specifically tailored for this dimension to ensure a proper fit. These sheets typically come in sets that include a fitted sheet, a flat sheet, and pillowcases. They are available in various materials, such as cotton, microfiber, and linen, allowing consumers to choose based on their comfort preferences and budget.