Tenn Well Natural Silk Pillowcase, 19 Momme Pure Mulberry Silk Pillowcase with Hidden Zipper, Queen and Standard (White) MATERIAL: 100% Pure mulberry silk on both sides, 19momme 400 thread count, very silky and comfortable to sleep on. FUNCTION: Most natural anti-aging products, the silk pillow can prevent the wrinkles and help with the bed head problems. GOOD FOR HAIR: Soft and smooth silk pillow protect your hair from breakage and make it silky, especially the curly hair. ZIPPER END CLOSURE: The zipper is strong enough so the pillow will not slide out and disturb sleep! TEMPERATURE REGULATION: Pure silk is skin-friendly and moisture to help feel cool in summer and warm in winter compare with other pillow covers.