40 inch Number Balloon Wide Application: suitable for all needs balloons place. special birthday, wedding anniversary, graduation anniversary, holiday celebration, business, big events, school class parties, party activities.40 inch Mylar Balloon:With automatic sealing function, Stronger self-sealing than ordinary balloons,so do not need to tighten with your fingers, normally last over 1 week.40 inch Foil Balloon: Thickened than Market Average. High quality biodegradable balloons. Made of high quality foil,Strong and long lasting,color uniform,and you wont have to worry about them tearing or bursting when inflated.40 inch Balloon Party Supplies: shining silver color mylar party balloons, balloons enough to decorate your party,if you want have a perfect wedding anniversary or birthday parties,choose our mylar ballons,Is definitely a perfect party decorations.40 inch Helium Balloon:The 40 inch diameter balloons are Made of high quality foil, and inflating with a pump is strongly recommended The balloons can be filled with helium or air. They are safe to be used with any of these two materials.When inflated with air or helium kids should use these under the direct supervision of an adult.