FeaturesAdjustable Weight, Side to Side Scrolling, Programmable Buttons, Grip, LED Lighting, Ergonomic, Silent, Keyboard Modifiers, Scroll Wheel, 4-Way Scrolling, Adjustable DPI, Thumb Button
Excellent product. It has more features than other ergonomic mice. I replaced an old ergonomic mouse with this product so I am already familiar with the use of one. Only drawback if using a keyboard behind it is that the controls have a high profile and can accidentally be bumped while typing. In this case I try to hold my hands higher while typing. Scrolling wheel does not have notched amounts of scrolling, which is not a drawback, but something else to get used to.
Good egonomic mouse. The product is damaged, I will fix it,
I like the concept of the RollerMouse, and the 9 programmable buttons of the Free3. This is much about your personnal taste (in he US ContourDesign runs a "30 day free trial" program).
The wired model of the RollerMouse Free3 has a fragile point: if you carry it every day the USB cable ends up damaged (I guess it would have been better in the original box, but this box did not fit into my rucksack). I had to solder a stronger braided cable.
The seller clearly showed that the cable of this product is damaged. I am going to replace likewise with a braided cable.