The Logitech Wireless Illuminated Keyboard K800 works with my Logitech Wireless Trackball M570 with the unifying software which save USB ports. The keyboard is so cool and lights up when your hand come close to the keyboard. That help preserve battery life. It work's as fast as a keyboard that is plugin your compute. Recharge your keyboard though your computer's USB port even while you're using it. I have had it for a month and it is still full of power and I haven't turn it off. I like the way the key feel too. Just buy one and you will see just how great this Keyboard is, I'm very happy with it. Logitech hits another homerun with this Keyboard.

Low Profile keys are perfect for programming or any task. Board height is also slim. Long charging cable allows wired usage if desired. Lit keys stay fully illuminated while wired. When using as wireless, keyboard senses when your hands are removed from the keyboard and illumination turns off - saving battery. Instantly illuminates keys when your hands are sensed near the keyboard. Lights return even before pressing any key. Four lighting levels easily controlled using function key and F5 (lower) or F6 (brighten). Battery level indicator displays charge using 3 bars.

Overall, this is a great keyboard. I'm a heavy user and the rechargeable batteries did not require a recharge until six weeks later after the first charge. That was much better than I expected. The lay out and feel wasn't much different than my other 10 year old Logitech keyboard that bit the dust. The only improvement I recommend is to extend the auto turnoff illumination time longer. It turns off after 3 seconds. That is annoying when working in low light. There is the option to turn on keys all the time but I prefer the auto turnoff to extend battery life. One thing to note is that my Logitech MX 700 mouse now has some minor compatibility issues that may be from wireless signal interference between the mouse and keyboard. So if you have an old Logitech wireless mouse you may need to upgrade the mouse as well.

Logitech K800 Wireless Keyboard was a wonderful investment for me. Adjustable illumination of key backlights are great for working in any lighting environment. Rechargeable battery has a long run time. I was most impressed by the touch of the keys, easy yet solid feeling. Many features at a great price.

The keys are so sweet to the touch and if you remember all the "F" functions, it is even better. Plus, it is lit in complete darkness.