The Happy Birthday balloons come in a pack of six and are made from natural rubber latex. There are two balloons each in the pastel colors of mint green, pink, and light purple. When inflated, they have a diameter of approximately 22.8 cm and are printed with the phrase "Happy Birthday" in white. If you pre-stretch the balloons before inflating—by pulling them apart with your hands and filling them with air to about half and then letting the air escape—the balloon will become softer and more elastic, allowing it to be filled with about 5-10% more air or helium. The latex balloons are delivered uninflated and can be filled with either helium or air. They can stay inflated for several weeks. Create a fantastic atmosphere for your next party. These balloons are perfect for decoration or as a gift. Amscan offers everything you need for a children's birthday party, a garden party, or occasions like Valentine's Day, Carnival, Easter, Mother's and Father's Day, the start of school, Oktoberfest, Halloween, St. Martin's Day, St. Nicholas Day, Christmas, or New Year's Eve.