I am since 1995 Fan of the Microsoft Natural keyboards. I'm working on any PC that does not have such a keyboard, accordingly, I bought myself an entire stock, as time expired production. Because I was pleased with the successor "Elite" in any way. Although the first Natural Keyboard has very good shape the last 11 years (both the absolute perfect mechanics and the bi-annual cleaning Marathon of keys with denture cleaners) my office copy was by UV exposure over time unsightly white of beaming it mutated to nicotine yellow , As helped also no more scrubbing. A successor was needed. Namely, the ergonomics should be just as good as my beloved Natural Keyboard. At Amazon, I found the Microsoft Natural Ergonomic Keyboard 4000 and due to the low price I did it once ordered me blind. Here is my experience about this: The keypad is just as divided as the first Natural Keyboard. Unfortunately, it is arched significantly flatter. In a direct comparison are my hands on the old keyboard to ergonomic. But that's struck me is probably because I have not touched for 11 years with no other keyboard as the Natural Keyboard. Now, after a week I notice the difference for 4000 barely. So is a matter of habit. You can also mitigate this effect, in which one works out the rear Füsschen, so that's a little more inclined to the front keyboard. Unfortunately, one loses the non-slip layer on the desk, because the feet are not gummed and accordingly a rubberized foot forward can slip around. Also, the keystroke is much softer and spongy as the old Natrual Keyboard. But that seems to be probably fashion at the moment. A positive feature is an on the might depart palm rest leatherette. The only question is, when the blunt strucktuierte surface imitation leather smooth, shiny and greasy aussieht.Tolles feature, I also think that the 10-block additional four keys "(", ")" "=", and "Backspace" was extended. Otherwise, the extra buttons hold back positive. "Home", "Search" and "E", then four buttons to control a media player, a start button for the Windows calculator and 5 keys for free programming. More must not be real. One can argue about the meaning and purpose of the "Zoom" button, because I work a lot with Office programs and the button will work even in my CAD program I use now more often. The cable is long gratifying, though not as long as the first Natural Keyboard. Unfortunately, no PS / 2 adapter is also supplied. Why not? To waste USB ports for keyboard connection I consider foolish, the free PS / 2 port for use anywhere I can. Conclusion: The Natural Ergonomic Keyboard 4000 is a good replacement for the Microsoft Natural Keyboard from 1998. Unfortunately it happens not quite to the old keyboard, but it is still better than anything Microsoft has released since the 1995 model.