Cute Silver Alphabet Letters Balloons Happy Birthday Party Decoration Aluminum Foil Membrane Ballon by ZooYoo The balloon is thickened and the Material is aluminum film. Less than 18 inches of foil balloons are not able to float. DO NOT FILLED WITH HELIUM for 16 inches balloons, its CAN NOT FLOAT. But you can stick them to a string and hang up these letters or stick on the wall, that's also very beautifu. Written on the card packing balloon is 14 inches, the actual size is 16 inches. You can use the pump or Straw to blow the balloon.When the inflation is completed, please put the ball to pinch flat, the ball comes automatically sealing glue! Because of the particularity balloon, we cannot open to check the balloons. The disqualification rate is 0.5%.If have any quality problems, please contact us and we will help you solve it. You can search "ZOOYOO BALLOONS"to discover more balloons for birthday / party / wedding / propose / anniversary / baby birthday