Specially designed curtains for soundproofing to block outside noise coming from windows. Noise reduction up to 25 dB. Curtains are made of layer of sound absorbing blankets Producer’s choice grade and a special Limp Mass Membrane reinforced to be used as a curtain. 48 x 48 inch curtains weigh approximately 20 lbs. Curtans can be made to a custom legth. Made to order.