Magic reusable blackout is a temporary window blackout, for keeping out light enabling a better night's sleep. Magic blackout uses static to stick to most hard surfaces. No need for tac or glue, magic blackout leaves no marks on glass and easily peels off to be reused again. As well as blocking out light, magic blackout will also reduce heat and help keep rooms cooler.the material should last for over a month, but it may crease in hot conditions and naturally loses its static charge over time, particularly if you remove and re position sheets a number of times. The sheets can be recharged.this versatile magic blackout has a number of uses, it is ideal for children's nurseries, night shift workers, new homes that don't yet have curtains, caravans and mobile homes, motorboats and yachts. They are also great for when you have overnight visitors, or for holidays and when you are travelling, enabling a restful night's sleep when you are on the move.magic blackout can also be used with projectors and interactive whiteboards. This product is certified 100% no single use plastic