50th Birthday Keep Calm It’s Your 50th – Foil Balloon 17 ” HX Keep Calm 50th Birthday Helium Savers XL®. At 17″, they are only 4% smaller than standard 18″ balloons, but you’ll use up to 20% less helium. Made with Anagram’s XtraLife® film so they retain helium 3-5 times longer.
