Excellent prop. I have the perfect bill to egg routine for this prop. You can show it and then conceal it easily in your hand. Well made and made to last. I will say that it does not squish down as small as most sponge balls. You can squish it down to about half it's size. That is enough to conceal a ball in your hand, but you would need to have pretty big hands to conceal more than two. You could hold make it appear you have a couple balls and produce four, but you probably couldn't conceal all four.
All in all, top notch and definitively will be of use.

I wish I had read the reviews here before purchasing this item. I hope to eventually find a use for these (they DO look good), but they are not compressible enough for any realistic sponge ball type routine.

The sponge tennis balls look great until you put them side by side with the real thing. Also, I assumed that they were "super soft" which they are not.

These balls are the size of true tennis balls. To use them in a sponge ball routine you really have to squeeze them hard. Overall the balls are to hard and big to make a trick work unless you have giant hands. The average 6 foot person has hands to small. I would not buy these balls again.

Gimmick is really well made. My 18 month old son was very fascinated by it.

I love these things and use them all of the time.
Some people seem disappointed by these, but you just have to train your brain to realize that they are very different from the standard sponge ball material that we are all used to. You just need to think creatively with these. They are fantastic because they are a total ringer for something that the audience is so familiar with. Everybody knows what a tennis ball is. Not everybody knows what a sponge ball is. It's very deceiving to have something that looks just like a tennis ball, compress into the palm of your closed hand!
These are perfect for loads in cups an balls and they really do pass as tennis balls even very close up. I've never had a spectator suspect a thing. I even do an all out tennis ball vanish with this product in my show and it brings down the house every time.
Now I'm totally disappointed that these don't seem to be available anymore. I certainly hope that Penguin can contact the manufacturer and get some more of these in. I would buy more in an instant.
I love love love them.
Penguin please restock these. I would pay double!