This sheet from Juna is an envelope sheet that goes over the top mattress. This sheet is always smooth on your bed and fits it perfectly. The sheet fits top mattresses between 4-8 cm in height. It is made of closely woven percale in 100% cotton. Useful information about Juna Percale Envelope SheetSize: 140 x 200 x 4/8 cm Material: 100% Cotton Wash in max 60°C, although we recommend 40°C, as it is proven that lower temperatures are just as efficient as higher temperatures.Can be put in dryer