Having party under the sea? Perfect for the girl who loves mermaids and world under the sea. 18" Mermaid Shine Foil Balloon. You can choose options for either "Uninflated" balloons or "Helium Inflated" balloons in different prices. Uninflated balloons are balloons with no inflation that sold in flat folded condition. Helium inflated balloons come attached with curling ribbon string but not shippable internationally.