The wheel became loose in half a year (but this is a4tech and this situation was expected). BUT - the wheel still works without scrolling! The only thing that is frustrating is that the mouse is forced to occupy one of the two usb ports on the front panel of the system unit due to a short wire (I did not experiment with an extension cord - they only cause trouble) Otherwise, great stuff! be sure to set the polling frequency to 500 in the settings - this will get rid of possible glitches with the cursor jumping over pixels.