1. Polyester2. Important: Accurate measurements are essential to choosing the right size for your classroom windows. Before placing an order, please measure the window size first, preferably add 3 inches to the glass width and 3 inches to the length, and then choose the size to ensure the right size. 3. Package Contents: Made of high-quality blackout polyester fabric, sold as a whole piece. This blackout curtain is available in a variety of colors and is suitable for more classrooms, floor-to-ceiling windows, terraces, living rooms, kitchens, and home offices. 4. Easy to use: Unlike many blinds and blackout curtains, this product does not require any tools, hardware, mounting brackets, or drilling. Strong adhesive tabs secure the blackout curtain in place. Simply loosen the Velcro strap at the top, the blackout curtain will fall over the window, and then press the bottom of the blackout curtain into place to completely block the view of intruders. 5. Blackout and Privacy: These soft and durable door and window blackout curtains use innovative triple weaving technology. While ensuring the blackout effect, it is also necessary to ensure that the classroom is completely blacked out to effectively protect everyone's safety. Our blackout curtains are more diverse than blackout paper or blackout curtains.