Steve Spangler Science WINDBAGS, 4 Pack – Blows Up in 1 Breath – STEM Activity for Kids – Easier to Inflate Than Regular Balloons – DIY Science Toy for Ages 4 and Up – for Classroom and Home Use

Follow the instructions and these work great. I used these for a STEM presentation for K-8th graders. They loved them. Offers an opportunity to teach Bernoulli's Principle.

I love Steve Spanagler products. These are great fun. It only takes one breath to inflate those bags. They are big which kids like. My grandson loves them. I wish he still sold the giant windbag that is about 20 feet. It flies in the air. You need a string so you don't lose it. These are a great alternative though. The kids had hours of fun. Great buy!

Lasted less than 30-mins before puncturing. Difficult to fill firmly and tie/seal.

This was a fun and enjoyable, while it lasted. Bags got holes, rather quickly. But the kids fully enjoyed it!

I used this in the classroom at the beginning of the year. They do "pop" easily so beware of that but it gets the point across when we practice peaceful breathing.