Unique Industries Put up the bat signal at your kid s birthday with these Batman Foil Balloons. Measuring 18 inches when inflated (they ship un-inflated) these balloons feature the Batman logo with Batman s silhouette in the background. These balloons can be inflated with either helium or air. To inflate with air use a balloon pump or a plastic straw. Once inflated you can tape them to a wall or if they are filled with helium you can mix them with other balloons to create a balloon bouquet. They also make a great addition to a photo booth. For the ultimate Batman birthday party combine these balloons with the rest of our Batman themed party supplies.