Aluminum foil material, metallic luster ball, color uniform, beautiful ball, can be used repeatedly, easy to fill and deflate, not throw it away once, after the completion of the inflatable, put ball outlet pinch flat and ball mouth comes automatically sealing glue, any balloons filled with air is not gone, can float up only red hydrogen or helium, when filling hydrogen, you must be away from the fire source, Helium is inert gas, the cost is high,  but it is safe.