Outgeek Happy Birthday Balloons Banner, Foil Balloons Letters Balloons Mylar Balloons for Birthday Party Decoration Made of high quality aluminum foil balloons and auto-seal Measurement about 16 inches of birthday foil balloon, many kinds of cute mini printing pattern and different color for your choice Perfect for decorating the babies, kids, adults birthday party with this lovely "HAPPY BIRTHDAY" mylar letter balloons Please inflate the gas slowly until 90% filled and leave away the fire, because of the thermal expansion This foil balloon is helium quality and suitable to inflate with both helium or air(the inflate pump not included)