Make your space-themed parties out of this world with our Balloonify Mylar Astronaut Balloons. These astronaut foil balloons are crafted from durable mylar that ensures they maintain their unique shape throughout your event. Featuring a self-sealing valve, these mylar spaceman balloons can be filled with either air or helium by use of a pump. Ideal for all occasions, these moistureproof space party balloons transform any gathering into a cosmic adventure. Reusable, these space-themed birthday balloons are not only a fun decoration but also a memorable choice for your celebrations. To reuse these balloons, gently deflate, properly store, and carefully reinflate without overfilling. Measuring 30.25 inches in length by 23 inches in width, these space birthday balloons have a striking presence that cannot be ignored. Shipped deflated in a 100 count box. These party balloons can be easily inflated with the included straw, providing you with full control to help avoid the risk of over-inflation. Electric air balloon pump (SKU: RWP1061) sold separately.