At times it does what it should. A loose connection so at the counter - but now the LED light goes out, despite charged batteries? or at the "guts"?
The off switch is important (to me), because the device boots up the notebook in standby mode movement of the mouse. But this switch is difficult to operate.
Since purchasing the supplied batteries have already been used up and replaced by batteries. And I'm not the PC daily ...
For less than 10 is probably to be expected just that.