Kindly remained:

• Since the aluminum foil balloon is not shrinkable, please slowly inflate the foil balloon. Inflate the balloon to 80% full with a hand pump, which is easy for controlling the air volume and avoiding burst it. If there are two aluminum films that stick to each other, be sure to stop the inflating, gently pull the two layers of aluminum films and then inflate.
• Please store the inflated balloons at a stable temperature. Heat makes the balloon expand, and cold makes it contract
• Sharp objects, unclean surfaces, direct sunlight, and excessive squeezing can easily damage and burst the foil balloon.
• If you accidentally break it during use, you can use clear tape to seal the opening.
  Please be aware the hand pump and the electric pump will only inflate the balloon with air, not helium.

Notice:

• 16" letter balloons will not float with helium