LOONBALLOON Alien, Space, Earth Theme Balloons, Robot Head. Quantity: 1 Accent your robot themed party with this 35in. large unique shape Robot Head foil mylar balloon. The perfect balloon for your robot party, this 35in. party balloon is great for setting the scene! 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.