This is a large helium tank which will fill approximately 440 11″ helium balloons. This tank holds up to 2000psi of helium (or 220 cubic feet) and an 11″ balloon uses up to 4.2 pounds (or .5 cubic feet) of helium. A 12″ balloon uses 5.1 pounds (or .6 cubic feet), which means you can fill up to 365 12″ balloons with a full tank. We offer helium tank rentals in two different ways. You can either rent a tank for $19.95 per day plus $.15 per pound of helium used or get a full helium tank which you can keep for up to a week for only $215.00 If you are going to use 1300 pounds or more of helium, you are better off with a flat rate. We also carry balloons, curling ribbon, balloon clips, and Hi-Float.