Sun 35" PartyDeco Foil Balloon sold flat (packaged) Inflated Size 70 cm (27.5'') Self-Sealing Valve. Suitable for Air or Helium (Straw provided) Inflate with balloon with helium at room-temperature leaving wrinkles around the balloon seam. Can be re-inflated. Average good float-time: 3-4 days but may last longer depending on conditions. Once inflated, avoid exposure to extreme temperatures. In cold air, the helium balloon will deflate slightly, exposure to warm air will restore proper inflation. Excessive heat could cause the balloon to burst. Caution: Do not release helium-filled balloons outdoors or near power lines. This balloon may conduct electricity. Misuse can cause injury. Dispose of properly. Helium gas should never be inhaled.