This colorful fabric has a bit of whimsy to it, making it a lovely sleep mask. My sleep masks are adjustable for a comfortable fit. These make wonderful gifts as well. ~The back is a soft black 100% cotton flannel, and I added two layers of fabric inside. ~The elastic strap is 3/8" wide. ~The mask is approximately 8"x4". I will ship this exact sleep mask using USPS. All fabrics are prewashed before construction with earth friendly detergent free of dyes, parabens, phosphates and phthalates. No softeners are used. Easy care instructions: Hand wash or machine wash in cold water using the Delicate cycle, lay flat to dry. Light iron if needed, avoid touching the elastic. Thank you for looking!