These are Made of high quality aluminum foil, about 32 inch 0 to 100 Number Digit and 16 Inch Happy Anniversary Alphabets, thick and auto-sealing, no leaks, can last for days when inflated. Give Your Big Party A Personalized Presentation With Foil Balloons! This Collection Of Metallic Balloons Features Every Alphabets From A to Z and Numbers, So You Can Mix And Match To Form Any Number Or Happy Anniversary Letters. Whether You'Re Celebrating A Big Anniversry, These Shining Happy Annivesary Rose Gold foil Balloons Are Perfect For Your Celebration. Mix And Match With Coordinating Foil And Latex Balloons accessories