Some have plastic outer cover some do not but they are all sealed! Luxurious Navy Silk: The Slip Sleep Mask in navy is crafted from mulberry silk, providing a soft and indulgent feel against your skin for a truly restful night's sleep. Complete Light Blockage: Designed to block out all light, this sleep mask ensures you achieve deep, uninterrupted sleep, whether you're at home, traveling, or taking a nap. Skin & Hair Friendly: The silk material helps reduce friction, preventing sleep creases and protecting your hair from damage, making it a perfect addition to your nighttime routine. Adjustable Comfort: With a flexible, elastic band, this one-size-fits-all sleep mask offers a snug yet comfortable fit, ensuring it stays in place without applying pressure to your eyes.