Have bought the thing about my two BKHS stimulate a little more to play, although I myself often play with them. Inserting batteries Open and was pretty tricky but ok. Turning the control dial is also designed something unfavorable. The thing turns and leaves but Spinning not particularly violent, the spring here. Unfortunately, the thing itself makes a lot of noise, if you can still run the thing on the floor it is nervig- not only for me but also for the cats. Should they are called are very cautious with it, unfortunately, is almost frightened, barely played it. Now try the gaming mouse to move independently from the device, but you can tell when the cats are rolling around the globe due to the already quite enormous size of the ball very carefully. The ball is maybe something for very large cats and are not particularly anxious, for my it was a false issue.