Celebrate that special someone as birthday with this fun 40 inch large unique shape monster Truck birthday foil Mylar balloon! combine a couple of these 40 inch Metallic balloon designs with a few of our birthday latex balloons to create a bouquet cluster to give someone as a special gift or to use as birthday party decor. This balloon includes a Self-Sealing valve, preventing the gas from escaping after it's inflated. The balloon can be inflated with helium to float or with a balloon air inflator. Balloon arrives uninflated. Monster Truck birthday foil Mylar balloon | 40" | Metallic.