Update: I've upgraded my stars from 2 to 4. To my surprise, my dog decided these pods are fun to stand on, after all. He's happy to use them for a variety of balance exercises. Turns out that he only needed a little time to get used to them. The price is much better than other pods, so this was a good deal after all.The "nubs" on these balance pods are very hard and too pointy! Ouch! I bought these to use in dog training, but the points are much too sharp for dog paws. I had tried another brand, made especially for dogs, at a local dog-training center and they were great; but that brand was expensive, so I bought these.We ordered these as a gift for our 4 & 7 year olds to use for obstacle course, etc to survive the winter indoors. The kids love them! My only complaint is how hard the bumps are. We have to wear shoes to walk on them.These might be ok for some folks, but they are quite huge, and not at all as in the picture . Itreally takes two hands to hold one, not one hand. I am returning to a former similar but better madeproduct , which cost much more but ultimately much better functioning. These really do not functionfor therapeutic use, in more ways than one. Another way being quite uncomfortable , picky spines.Sturdy and best price. I use em for serious, almost painful foot massage.Good product. Only thing I didn’t like was the spikes were a bit too pointy. No problem, clipped the tips off with clippers. Now they are perfect!These are really hard. I don't like them, but my husband likes to stand on them, he says it feels good on his arch.This item was a little too rigid for our needs at first. I was hoping for something more playable or soft but we have found a few excesizes that work with this spiky ball.Use for Fastpitch pitching balance drills and these work great! They are definitely hard but work great for what they are intended.Quality product but doesn’t meet my needs. I purchased for my kiddos to play on. They enjoyed them but they’re such a hard plastic that both my kids hurt themselves on them a couple times over the past 2 days.I had expected them to be softer.This item is supposed to be used for balance . Should be slightly soft. The ones I got were rock hard and air pressure could not be adjusted. Not at all like ones at physio or the gym. They are of no use to me.The instruction sheet was not included. So I now have 4 useless plastic domes. They are extremely hard plastic so I doubt they will be useful for their purpose of exercise. I’m debating if I will send them back and lose money or see if any one else wants them.they are firm enough to hold my 200 Lbs frame up I use them to improve skating balance. my kids love them too seeing who can stand the longest without falling........It slips easily, the plastic is very hard and I would definitely not buy that again.