Party balloons are mostly made of a natural latex tapped from rubber trees, and can be filled with air, helium, water, or any other suitable liquid or gas. The rubber's elasticity makes the volume adjustable. Premium-Quality Metallic Balloons will for every celebration.Size :10 inches round,Blow them up with either your mouth, air balloon pump, or helium. Balloons are used for decorating birthday parties, weddings, corporate functions, school events, and for other festive gatherings. The artists who use the round balloons to build are called "stackers"