LOONBALLOON Birthday-over-the-hill Balloons, 18 inch OLDER THAN DIRT, Celebrate that special someone’s birthday with this fun 18in. round Older Than Dirt foil mylar balloon! Combine a couple of these 18in. 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. Older Than Dirt Foil Mylar Balloon 18in.