100% Pure Mulberry Silk. Key Benefits: Helps to reduce signs of friction, stretching and tugging on delicate facial skin Silk fibers promote longevity of facial products Reduces pressure on delicate eye area Prevents visible signs of fatigue Promotes a restful night's sleep Recommended by dermatologists, plastic surgeons, hairdressers and beauty experts Sleep mask dimensions are 8" x 3.5" Awards: Winner ‘Beauty Icon Award’ Harper’s Bazaar Beauty Icon Award 2022 Winner ‘Best Sleep Mask’ Women’s Health 2021 Slip on over eyes. For maximum results, use for eight hours daily. Slip pure silk pillowcases are of the highest quality so they are machine washable, but they are still silk and need as much care as we can give them. Always use a pH neutral detergent and/or fabric softener. Silk is a natural fiber and washing in a solution that's too acidic or alkaline can cause the silk to harden in a single wash. If you can't find a detergent that specifies pH level, opt for one that specifies silk. If your machine doesn't specify exact heat settings, wash on either cold or just one level above cold. If you wish to maximize the life of your pillowcase, hand-washing is the ultimate method.