The two colorful balls were individually packaged in clear plastic bags and were a little smaller than I had expected - about 5 cm in diameter. But the first gripping I realized quickly that they can not be greater, otherwise the compression effect would be not so ideal. As soon as you the parts in hand, makes fast the "addiction" effect noticeable: You sit while watching TV or talking, while a hand always pursues its Knetarbeiten. If the balls somewhere visible, then the temptation of accessing for all family members is always high. ;-)
I can not give any medical opinion on the Thera-Band hand exerciser. But its application is noticeably relaxing for me and doing the hand, wrist and forearm apparently quite good. The nice thing is that this is not really hard sporting exercise to which you have to overcome. Kneading the balls instead goes by itself in the background, without having to think about size.
Although I find enjoyable the red ball of its hardness and consistency, it can be actually worked like modeling clay. It is quite soft and can be relatively tiring and long kneading and the effect is achieved as on the method of administration, while the blue ball to work quite hard and stressful. Beginners should therefore be red and / or green grip or alternatively order a yellow / red combination. By the way there is for the balls and a stylish wooden storage box, where four of them fit in (search for: "Thera + Box").
For consistency: The Thera-Band hand exerciser consist of a special plastic that something chemical smells especially in the beginning. With the soft, red ball, I sometimes during kneading the impression that I could destroy him, but those things are obviously very robust. The shell of the balls feels like powdered and has a tendency to stick to very light hand.
My opinion: you will be disappointed in any way. Rarely one can do with his health as little Euros a favor. I would imagine that particular contemporaries benefit from the Thera-Band Hand trainers, who are exposed to at work one-sided burden of PC keyboards. Moreover, the kneading of the Thera-Band Balls should incidentally also act calm. And if necessary, they can throw it to her boss. :-)