Celebrate your child s birthday with these fun and colorful Batman and Iron Man balloons. Each medium-sized balloon measures 22x25 inches and can be filled with air or helium. The self-sealing valves make them easy to inflate and keep the air or helium inside. Perfect for decorating the party venue or as a fun gift for the birthday boy. Made of durable foil material these balloons are sure to add a touch of superhero excitement to the special occasion.