These are Made of high quality aluminum foil, about 28 inch in size, 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 Helium Baby shape Foil Balloons for baby shower party and baby welcome party ,Whether You'Re Celebrating A Big party for twin boys, twin girls, baby boy, baby girl, twins boy & girl welcome party & These Shining Baby shape blue and pink color foil Balloons Are Perfect For Your Celebration. Mix And Match With Coordinating Foil And Latex Balloons, Polka dot balloons & balloon accessoriesBaby Shape 28" Inches foil Balloons for twins (boy & girl) X 2Self sealing mylar foil balloon, will remain inflated for weeks, can be "topped off" with helium when neededFor all occasions including shower party, welcome party, 1/2 year birthday celebrationPrinted on both sidesAvailable Polka Dots Happy Birthday Alphabet Letters