EIGIIS 2.4G Ergonomic Trackball Handheld Finger USB Mouse Wireless Optical Travel DPI Mice for PC Laptop Mac Left and Right Handed

This is actually a great little device but think carefully before you get one because it may not be for you. It requires an entirely different type of dexterity when compared to a standard mouse or trackball. First of all, you are going to have to decrease the sensitivity or speed of your mouse. The reason is because when you are operating the trackball it is relatively unstable in your hand and it is subject to small hand movements that would not be obvious with the standard trackball on your desk. Finding the right grip is another tricky part. Initially I was trying to hold it like a pistol squeezing the "trigger" in order to make a left click. This is totally wrong, at least for me. You have to thread it on your index finger like a ring and let it sit just beyond the second finger joint. When you are going to do a left click do not think of it like pulling a trigger but rather squeezing a rubber ball. With it in this position your thumb can alternate between the trackball and the scrolling wheel. Highlighting is definitely a totally different skill. You have to master the ability to squeeze the trigger and roll the trackball all at the same time. When I use a regular trackball I keep my thumb on the ball even when I am left or right clicking with my fingers however with this device I position the cursor and then typically lift my thumb off the trackball before I give it a squeeze to do the left click. It really is a different skill set from what you are used to but if you take a little time to learn how to do it I find it extremely intuitive. I suspect I will be replacing all of my pointing devices with this one as time goes on. ONE WORD OF CAUTION: this is not a good option for you if you frequently have to switch between using your mouse/trackball and typing on your keyboard. Unlike a standard trackball we can just move your hand from one device to the other, you have to take this off your finger and put it down in order to type and it will be very annoying if you have to switch back and forth frequently.

I have been using this as my primary (only) mouse for more than a year, and there are several things I really like about it, as well as a couple of glaring drawbacks.Pros:- Ergonomic and ambidextrous: It can be used with either hand in any position. This helps avoid fatigue/carpal tunnel issues. I can easily use it standing up, leaning back, or sitting with my hand in my lap, and if one hand is tired I can use the other one.Cons:- Doesn't allow right/middle clicking while moving the pointer. With a regular mouse you can hold the left click button, right click button, or middle (scroll wheel) button while moving the pointer. With this you can use your index finger to hold the trigger (left click button) while using your thumb to move the wheel. However, right-or middle-clicking can only be done with the thumb, which prevents you from also using it to move the pointer. This is a fairly rare use, but still noticeable, for example when you want to copy (not move) a file from one folder to another by dragging and dropping, or for actions in certain games. When I want to do this with this mouse I have to use one thumb to hold the button and the other to move the pointer, which is a bit cumbersome.- Uses batteries rapidly. It only uses a single AAA battery, which gets drained every few weeks. Turning it off when not in use may extend this, but it does seem to have a "sleep mode" feature, in that if you don't use it for a few minutes and then move the ball nothing happens, but clicking one of the buttons once will wake it up. Not sure if this saves as much power as turning it off would. Just make sure you have a steady supply of AAA batteries on hand if you're going to be using it extensively.- Replacing the battery is easy, but removing the ball to clean the rollers is tricky and requires a specialized device. Basically you have to have something very small and pointy but also very strong (i.e. a hard, sharp piece of metal; a paperclip wouldn't work; I use the point of my cuticle nippers) to stick into a small indentation to rotate the clasp, which inevitably ends up being damaged in the process because it's made of plastic.- I've bought it several times in the last year because the right-click buttons inevitably break and fall off after a couple months of use. Fortunately there are two, so when one breaks there's a backup, but eventually the second one breaks off as well, and then the device becomes useless. It's not too expensive, so buying three or four per year isn't prohibitive, but it would still be nice if it was designed to last. I make a point of having a spare one on hand for when the current one breaks.Overall the pros outweigh the cons, and so far I haven't been able to find anything better for freeing my hand from the desk, but it definitely has room for improvement.