Simply attaching it to the curtain rail runners prevents cold air from entering from the window, reducing the drop in room temperature and improving heating efficiency. Fabric durability UP! ● Allows plenty of sunlight in, so the room doesn't get too dark. ● Easy to install using the curtain rail runners. (Includes S-hooks for installation) ● The curtain hem can be freely cut with scissors to match the height of the window. Size: Approximately 110cm wide x 145cm long, 2 panels per pack, 2 packs total. Available for immediate purchase.