The Happy Birthday balloons come in a pack of six and are made from natural rubber latex. Each pack includes two balloons in pastel colors: 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 stretch the balloons before inflating them—by pulling them apart with your hands and filling them with air to about halfway before letting it out—the balloon becomes softer and more elastic, allowing you to fill it 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 gifts. Amscan offers everything you need for a children's birthday party, a garden party, or occasions such as 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.