Perfect 42-inch Number Balloons for 40th 21st 30th 18th 60th 16th 19th 4th 50th 1st 31st 2nd 3rd 5th 66th 39th 20th 10th 70th 80th Birthday Balloons,Anniversary, 2019 Graduation, Class of 2019, Senior Picture Day, New Year Eve,Wedding, Ceremony and Other Party Supplies. Features: Foil Helium balloon, empty balloon is 42 inch, after filled with helium or air, it's 40 inch. Material: aluminum film nylon, not easy to explode and leak, bright colors, full of numbers. Ideal for children's birthday parties! The balloons can be filled with air or helium. Use Advice: For an impressive display, combine them with tissue paper decorations into a balloon chandelier, use them in a party backdrop to highlight your dessert table, or add coordinating foil balloons and curling ribbon, you can easily create a balloon bouquet. WARNING: CHOKING HAZARD- Children under 8 yrs. Can choke or suffocate on uninflated or broken balloons. parents supervision required. Inflate slowly,just fill 90% of the balloons’ space that could allow the balloon to expand completely.