It's made out of the same (similar, at least) material as the egg, if you've ever used one of those. It's just thicker, more durable. Easy to clean and dry. I suppose if you're all about being discrete, you could say it's a loofah or something.
Pros
3.43 x 3.43 x 3.39 inches; 12 Ounces
Cons
Requires significant lubrication to function properly, which can be messy and time-consuming