These helium-free 17" balloons are the World's Strongest Balloon! Specially engineered plastic polymers with metallic flake keep them looking shiny, brilliant, and fade-free for months to years! These are the only internally seamless air-filled permanent and reusable balloons on the market today. Whether you are in an arctic, tropical or extremely windy region, no balloon can stand up to the elements better than DuraBalloon®. They are made to last months to years! Choose from the colors listed.