Effectively blocks daylight: To create a dark sleeping environment and maintain their sleep routine, anywhere Lightweight design: Regular = 320g. Large = 680g Suction cups: Attaches to your window with long-lasting suction cups along all four edges Adjustable fit: Fastenings mean you can adjust the size and get a perfect fit for your window Travel-friendly: Folds away easily into the travel bag and is compact enough to fit in a suitcase or overnight bag