300 Day Satisfaction Guarantee: All Rayhee products are guaranteed to give you 100% satisfaction in every way for 300 days from the date of purchase. If for any reason you are not completely satisfied, you will receive a replacement or refund. You won't believe how smooth it feels!The Silk Sleep Mask Using high-quality, all-natural mulberry silk, this mask is constructed to be thin enough to be comfortable when sleeping on your side, while maintaining the soft, supple feel.Our natural silk sleep masks not only feel smooth against your skin but also hypoallergenic, great for those with sensitive skin. Mulberry silk is the fabric of the emperors. It is the most elegant of all the silks with a luminous sheen and a smooth touch. Buy for yourself or as a gift or consider it an investment in your travel accessories. Everyone will love the beauty and SIMPLE COMFORT of this silk.Why using a sleep mask? The hormone Melatonin regulates the day-night cycle of the human body and controls the recovery phases during the sleep. For the production of this hormone, the human body requires sufficient darkness. Lightness prevents the production of Melatonin. Even a little light caused, for example, by a digital clock can be a disturbance. Sleeping masks however provide complete darkness for your sleep.Sleep masks- what for? - if you want to sleep while travelling, e.g. on airplanes or in trains.- if your bedroom cannot completely be shaded by black-out curtains and you want to sleep in. - if you cannot fall asleep because your partner wants to read or watch TV. - if you are looking for perfect relaxation during yoga, wellness or meditation.