Kicko 5.5" Puffer Balls for Kids - 12 Pack with Assorted Colors - Blue, Green, Orange, Yellow, Pink and Purple, with Loop - Sensory Stress Relief and Therapy Toy - Party Favors, Goody Bag Filler

I don’t know how they measure the size BUT! I hope this helps you. I ordered a set of 6 (different brand—Playbees) before I ordered this set. The size said 5.5. They were comparable to the size of a softball. I received this set today and even though it also said 5.5, these are comparable to the size of a baseball. I hope this info helps others. Both sets are great, but sizes are different.

The particle was exactly what I ordered

I purchased these for my office. They liked them. We throw them at each other to get the other person's attention.

My pet duck just loves these!

Bought for teacher prize box. Kids love them.

A bit on the smallish-side...they are 5.5" from the very tips of the little tentacles, the ball is more like golf-ball diameter. My hope was that they would work as well as the cheap dollar store "puffer-balls" and stick to windows and walls etc., eventually walking down the wall etc. .... nope. They tend to develop a hole in the center ball and after that they flatter out. For the price, as an item to put in a Xmas sock, or birthday party favors they ae fine.

In the nursery or in the pool, these balls are a huge hit with our 3 yo and 1yo grandkids.

My son loves these to meet his sensory needs, I love how each one is individually wrapped.