Wide band makes it much more comfortable to sleep with as you can roll on your side and you don’t have to lay on any plastic adjustable pieces as you do with many adjustable sleep masks. It is made of 100% TENCEL. It's designed to block out light and provide a soft, silky-smooth, and cool-to-the-touch feel. The mask is naturally breathable and wicks away moisture, making it suitable for hot sleepers. It also actually stays put all night long.