What's the name of the floating balloon sold in the park?

Color balloons or hydrogen balloons. This kind of balloon is filled with hydrogen, which can float in the air, forming a colorful, light and elegant picture in people's field of vision, and becoming a kind of enjoyment and beauty in people's eyes. Colorful balloons in the park are designed to increase people's entertainment atmosphere, and they have also become children's favorite. People who buy balloons often want to surprise themselves or their family and friends, or decorate kindergartens, schools, parties, parties and other activities.