Developed for use by astronauts, these emergency survival blankets are lightweight, compact and have many uses. Mylar can retain 90% of your body heat and can be used as ground cover or a shield from the elements. Not only can these be a life saver by providing warmth, but they can also be used as a ground cover, to build a shelter, collect rain water, and as a reflective signal device. •Unfolds to 84 x 52 inches. •Made of durable aluminized polyethylene. •Weighs only 1.5 ounces (42.5 grams). •Flexible in freezing temperatures. •Dimensions: 84" x 52" Each Blanket.