Exactly, they do what they are meant to. Arrived on time, and have had a battering already, good fun great workout. Just one point, this is a piece of equipment that you could be sucked into using without a complete warm up, it is fun. Make sure your forearms are fully mobilized and stretched, including wrist flexion and extension, in fact take it right up into the shoulder.
I love theses ball's. I use these as pseudo atlas stones for lifting and throwing and catching once you pump them up a bit. Great quality, easy to clean with a wet flannel, why buy dumbbells or barbells that rust when this does everthing you need and a lot more besides.