Durable & Non-toxic: The 10th birthday balloons are made of high quality foil mylar material and have an excellent metallic luster. Number Balloon: The giant silver balloons have a gorgeous visual effect and are perfect for decorating for any activities. Apication: Foil number balloons are great for parties and events, especially birthday parties, weings, anniversaries, New Year dinners, etc. ease Note: The balloon seal is not fully opened, you will need to open it with a straw or a pump nozzle (ease do not open it too fast to avoid damaging the balloon) Tips: Aluminium foil number balloons are not flexible, ease do not fill them too much.Warning:Not suitable for children under 14 years. For use under adult supervision