Good but does not come close to the 6000

The 4000 mouse is cheap and certainly useful, but comes to the 6000, which is no longer sold anscheined, nivhcht zoom.
As obvious shortcoming is missing the 'back button' on the right - from the back - the mouse. She is also completely made of plastic and worse / more easily processed than the 6000.
So, I think that's very unfortunate, the base parameter is missing in the 4000 mouse, compared to 6000. The 6000 mouse was perfect compared to the 4000s and has on processing quality and functions fulfilled everything the 4000 does not provide.

Too bad Microsoft and I hope very back the 6000 mouse.

Therefore, a star Abtzug.

Conclusion: **** stars