I bought the x-large version and the diameter of the inflated ball is about 18 inches. Perfect for a 7 years old. The plastic has no smell. The inflation held up for over two months.

My boyfriend who I bought it for is almost 230lbs and it did not pop! We had a lot of fun bouncing around the house acting like kids again. We didn't use it outside though... I was too afraid it may burst. Easy to fill and the pump works well.

I got this for my son for his birthday and while it seems to be pretty well made, it is much larger than I was expecting. It will be a year or two before he can use it safely and that is quite a bummer. The colors are amazing though!!

Extremely disappointed. This ball was advertised as "Hopper Ball for Teens" I ordered for my 9 yr. old Grand daughter. She is large for her age is the reason I ordered the Teen size. I had also ordered 3 of another brand name that were for 3 siblings, I ordered them in age group listed as 7-9. They were a perfect fit for them. They are 20 inch balls. This one is an 18 inch. for a very small size child. MOST definitely not even for an average size 6 yr. old. She is so sad that everyone except for her received one, it came in a plastic bag, no paper work came with it on how to even return. I am disabled and without transportation to even make the effort to get it packaged up and get it to the post office. So I will eat the loss and give it to a 2 1/2 yr. old who lives next door. I gave it 2 stars due to the lovely bright colors. And it appears to be a high quality. False advertising though has caused a sad child. And a waste of money for me. Beware of the size when ordering.

Things just haven't been the same in the bedroom since these arrived. Great way to spice things up!