For the party decoration to be totally complete, you obviously need balloons :)
But if you want to preserve your breath, here is what you need: a helium tank.
This helium tank is made to inflate between 20 and 30 balloons (depending on the size of your balloons) and thus make it easier for you to inflate and keep your breath ;)
Very easy to use, you just have to use the main valve to open / close the tank. But when the tank is "open", nothing comes out until you insert the balloon to inflate.
Once the balloons are inflated, do not forget to close the main valve for storage.
Caution: Store in a well-ventilated place. Protect from sunlight.