Built-in Insulation- Nantes Curtains has a built-in insulation that has insulation material incorporated into its fabric or lining. These curtains can help to keep a room warmer in the winter and cooler in the summer by reducing the amount of heat loss or gain through the windows. Made of 88% polyester/12% nylon Grommet top header- This type of heading creates a clean, modern look and allows for easy opening and closing of the curtains. The grommets also make it easy to hang the curtains on your favorite curtain rod. Grommet top curtains are popular for their sleek and contemporary style, and are often used in modern or minimalist home decor. Fits a rod up to 1.35" diameter 100% blackout