Large Black

This mouse is only okay. I still wouldn't consider this a great ergonomic design because your hand--instead of resting horizontally like on a standard mouse, rests vertically on this one--which is not a natural position either. A tilted-grip design (like maybe 20- to 30-degrees tilted inward) would almost make this mouse perfect. The mouse feels light but is appropriately-weighted so movement is decent (though you'll still have to re-adjust to using different muscle groups for moving the mouse--which impacts precision, but it's just a learning thing--nothing bad). The material used for the grip has a good, non-slick feel, which is nice. The DPI button/function seems like an after-thought. There's no LED indicator for what DPI setting the mouse is in, so you need to push the DPI button to determine which setting you're in, and hope you don't accidentally hit the DPI button when trying to use the scroll-wheel. After a few weeks of use, I don't notice any malfunctions or missed-clicks or multiple-clicks, which is good. The scroll wheel is poorly implemented from an ergonomics perspective. If you use the scroll wheel a lot, you'll notice the clear potential for strain/overuse of your thumb from rotating the wheel forward and backward. While it might be less-intuitive, a much better ergonomically-correct method would have been a scroll wheel with an orientation perpendicular to this one (or at least angled somewhat), which moves more like left-to-right (rather than forward and backward), which allows you to simply "sway" your thumb rather than pulling/bending it--pulling/bending puts more strain on your thumb's parts because it has one less knuckle of movement relative to the rest of your fingers. If you scroll a lot, you'll definitely notice a bit of strain/use in your thumb's lower tendons. All in all, this mouse should alleviate standard-mouse strains. But from using it, I hope this isn't the best ergonomic mouse available (outside of a scroll-ball mouse). It's not a bad mouse, but it could definitely use some design improvements to be a much better ergonomically-correct mouse.

poor fit shoddy manufacture ----really pretty horrible ---hurt my hand , did not work well , ended up in garbage can!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I had used the Zero Tension mouse until 2 years ago when it simply came apart from usage. It was an excellent tool. I ordered the another one this past 1-1/2 weeks because of shoulder pain. It arrived and I was at first quite happy, until....... I discovered the DPI button located to the left of the wheel, (a new feature/bug) right where my thumb rests. For those wondering what DPI is, it means DOTS PER INCH. The setting is slow to fast. This mouse is poorly thought out. I do not recommend this Zero Tension mouse to anyone. Poor product engineering. Your thumb will trigger the DPI because it is, as stated above, right under your thumb and if you are simply working to playing a game it is just TOO, TOO, TOO easy to press. In gaming you go from super fast mouse response to molasses suddenly. Working, the mouse suddenly drags across the screen. The only fix you have available is to make sure your thumb rests on the very sharp edge of the mouse, yes, it is a SHARP edge of molded plastic. So it is uncomfortable and inconvenient to use this mouse. In a word/phrase - this mouse now sucks.

In my opinion, this mouse lives up to the hype. At first it was tempting to grip it like a joystick, out of habit, but it soon became apparent that one doesn't really need to. It actually feels kind of weird and wrong to grip it, as the shape of the mouse is meant to be functional without having to grab. The unit cradles the hand in such a way that the fingers can lie in a relaxed, natural slight curl. With the main axis of the wrist now perpendicular to the work surface, the wrist automatically goes to its straightest, most comfortable position without the user having to think about it. It has a surprising lighter-than-air feel, literally feeling like you're pushing a small block of styrofoam. It's more like you're just moving your hand, rather than moving a mouse. One important point is getting your work surface at the optimum level (forearm parallel to mousing surface), as having to reach upwards or downwards for the mouse quickly minimizes the benefits. I only give it 4 stars because it is only shaped for the right hand, and I would like the option to switch hands. I'm not sure if there is a left-handed version. But even if there is, it would be better if the same mouse could accommodate either hand. They could make it a little bigger, and mirrored the cradling shape on both sides.