Note: The number can fly with helium Materials: Aluminum Foil  Letters: 1pc/pack Color: Silver optional Size : 40inch/pcs  Package : ①1 number(40inch) ②Plastic straw x 1pc (5.7 inch)  Tip : All Aluminum Foil Balloons are detected by the machines , If air leak occurs while inflating, please press the inflatable hole or use tape to assist the automatic sealing of the balloon.  Any problem or you need help, Kindly contact with us , we will solve it for you at once.