SANWA Wired Ergonomic Mouse, Optical Vertical Computer Mice, Reduce Wrist Strain, (1000/1600 Adjustable DPI, 6 Buttons) Compatible with MacBook, Laptop, Desktop, Windows, Mac OS for Office & Gaming

First off, I did find the mouse to be very comfortable and ergonomic. I'm around 5'8", but with larger hands, and the mouse was a perfect fit. The material is that soft touch plastic, very nice feel. Wired, and worked no problem on Windows 10, no drivers needed.My main issue was that the polling rate was only 125Hz, the default for USB devices on Windows, and this meant the movement was choppy on high refresh monitors. With my 160Hz screen, I could notice noticeable stutter just dragging windows around or playing games. For reference, the Logitech G502 (which is what I am used to) updates at 500Hz and is butter smooth everywhere. Sadly, they don't seem to make vertical mice for gamers, I've tried about 7 or 8 different brands and I can't find one that is good for high refresh monitors. However, if you are on a 60Hz monitor and are not gaming, this is probably not an issue for you.Finally, the side has a blue LED that cannot be adjusted or turned off. This was slightly annoying, but I could have lived with it if the mouse worked otherwise. Sadly, I've gone back to my Logitech, even though it does make my wrist mildly uncomfortable, because I cannot stand the choppiness on all the vertical mice I've tried.EDIT: I decided to try the mouse again and I like it. Although it's not as fast as gaming mice, it is so much more comfortable and I'm willing to make a sacrifice of screen smoothness for my health and well being. This is definitely the most comfortable out of the 9 or 10 vertical mice I've tried. Very nice, so I'm updating to 5 stars.

Fast, precise, connected quickly, very comfortable. I especially like the feel of the surface material. I am happy with my choice.

I love the feel/form of this mouse. It works great, except the scroll wheel started getting sluggish (it stopped 'clicking' when scrolling) after about 5 months of use.

Anyone considering purchasing this mouse is likely experiencing some level of hand, wrist and/or arm pain associated with the use of a traditional mouse. That pain is telling us to stop the repetitive motion that’s causing us pain. Traditional mice create tension in the shoulder, arm, wrist and hand. That tension eventually progresses into pain, which is inflammation of the tendons, nerves, etc. We all know stopping isn’t a realistic solution, so what do we do? Change how we interact with the computer. Fix the tension and you’ll reduce the inflammation. Do nothing and you’re on your way to carpal tunnel or some other repetitive stress injury.The Sanwa Vertical Mouse simply rotates your hand which in turn rotates the wrist and arm. This rotation removes the tension giving the user a more comfortable, healthier way to use a mouse. You simply have to use one in order to fully appreciate the benefits.Mouse operation was as described in product description. It requires two AAA batteries (not included). Bluetooth pairing to my Mac Air was simple. Tracking is smooth and precise. Best of all, this mouse eliminated my hand pain. Loved it enough to purchase a second one for my wife!Seller is exceptional when responding to questions and concerns. You really do have to try this mouse to fully appreciate its benefits. Great product offered by an exceptional seller that might just eliminate your pain and/or protect you from a future diagnosis of repetitive stress imjury. My orthopedic physician recommended a vertical mouse and I’m so glad I took his advice.I’m pleased to recommend this product and the seller. Five stars is well-earned!

Update: After having this mouse for a while I will say it helps with my carpal tunnel. However, it doesn't help with my stress level when I have to continually reset it to get it to work. I've used it on two different laptops and experienced these issues so it isn't the computer, it's the mouse. It's doesn't stay connected. And sometimes, things just stop working, like the buttons. No clue why, but I have to take time out to turn it on and off, reset it, check the settings in system preferences, and basically baby it to get it working again. It's incredibly frustrating when it decides to misbehave while I'm trying to teach an online class. I'm guessing I'm going to have to replace it again because it just isn't reliable.As someone who is on their computer fulltime, ergonomics is important. I'm always testing out new mice to try to find one that is comfortable in my hand. I do graphic and web design so a mouse has to not only be comfortable, but accurate. So far, this one is pretty good. It occasionally gets a bit jumpy, but a few taps and it's fine. I don't know if that's the mouse or my bluetooth connection as I've had that issue with other mice.The scroll button is just sensitive enough that it's easy to use but you don't find yourself accidentally scrolling. I haven't programmed any of the extra buttons because I typically just use the two main ones. But the two thumb buttons could be handy and are in a good spot that feels comfortable to use. The mouse is very lightweight and easy to move with little effort. The bottom slides easily on both my mouse pad and the desk, although I still prefer to use the pad -- it's softer and quieter.I have noticed that my arm and wrist don't hurt as much when I use this mouse as opposed to my old one that kept my hand parallel with the desk. It took a bit of time to get used to holding my wrist sideways, but it does feel better. I don't do a lot of detailed graphic work with the mouse -- I use a tablet for that -- but it is sensitive and accurate enough to do what I need.So far, I'm very happy with this. It was the most affordable ergonomic mouse I could find and it's performing well.