Subwoofer a bit wobbly piles

Timer fine, not complicated. Magnetic and convenient to use, my six year old daughter uses it without worry.
By cons, when you press the buttons, holding the box if you push with your fingers on the small box in the stack, sometimes the timer went into a spin. A little more strength would have been appreciated.

Now I am notified so I pay more attention to the use but it is still a failure.
I am happy to have this model but I do not think the purchase if necessary.