Disposable Helium Gas Cylinder Capacity: 0.25 Cubic Metres of Helium Gas. The small disposable helium gas tank will inflate 30 of 9 Inch latex balloons, 15 of 11 Inch latex balloons or 12 of 18 Inch Foil Balloons The pack does not contain any heli-valves For best results, fill the Balloons 1-2 hours before your event. Average float time will vary depending upon the size and type of balloons. Balloons not included with this item