Non perforated installation - Unlike ordinary curtains, our classroom door window cover do not require hangers or screws.To maintain the integrity of the surface,we provide PET double-sided self-adhesive tapes for easy to install and disassemble. Just stick one side of the tape onto the clean and smooth surfacer and the other side onto the curtain and align the two pieces of tape to complete the installatio. When not in use, these can be easily rolled up for convenient storage. 100% Blackout - The classroom door window curtain use triple weaving technology, which can block 100% of light and bring comfort and privacy to the classroom. And it is made of flame-retardant materials to ensure safety. Long Lasting - The fabric is 100% polyester with silky and soft handfeeling, thick and wrinkle resistant character, thermal insulated, go well with classroom themes,easy to apply, and the rollability ensure they roll up and down smoothly. Easy to Maintain - They are thick enough and can be machine washed, drum dried, quickly ironed, or steam cleaned to ensure long-term use and easy maintenance. Size - Measuring accurately is critical to get the correct size for your classroom window. Before you order,please measure the window,It is better to add 3" to your glass width and 3" to your length before choosing your size to ensure a proper fit. classroom door window cover