This bright multi coloured Congratulations balloon is sure to liven up someones day. Know someone that has just achieved something amazing, congratulate them with this balloon. This round 17in. (43cm) foil balloon will definitely brighten up someones day. This foil balloons is designed to be filled with helium and is a great way to make a special someone smile when they're not feeling the greatest! When filled with helium correctly this foil should last approximately 2-3 days and then slowly deflate.