These large silver number balloons are 38 inches high when inflated. Each balloon is sold flat and require helium to float. The number 8 balloon will stay inflated for several days and can be filled with our disposable helium canisters. For best results we would recommend you inflate them a little less than a normal foil balloon on the day of you event for full use. The balloons can also be filled with air using a balloon pump. Each balloon features attachment tabs with holes in for ribbon and balloon weights to be attached. This enables you to string air filled numbers onto a line to hang them or secure helium filled balloons with ribbon.