Sleazy Stretch Sheets can be used alone or with a hood. Sleazy Stretch Sheets are made of nylon or polyester spandex. All Sheets are reinforced along the back to prevent over-stretching and include a fleece lined adjustable neck. Sleazy Stretch Sheets have adjustable rear leg straps with snap & hook closures. All sheets are available in 5 sizes. Sizing is calculated the same way as traditional blankets. Fleece sheets are durable and add warmth.