Unfortunately, very poor quality. The fish inside the balls must be inflated separately. The air escapes but so fast that they largely coincide again in spite compression. A safety valve would be useful here. The same goes for the ball in. Nice idea, unfortunately, poorly implemented and therefore - even if the balls are cheap - I advise them to buy these balls. Basically they can be thrown away immediately, because the system is working so bad and why the money is too much of each. (Not to mention the garbage that is produced because of it.) Sorry, no buy recommendation.