I reviewed the Tetra Mouse a while back on this blog. I've found it to be a reliable and low cost assistive device for my computer.
The maker of the Tetra Mouse recently left a message about an updated model which I wanted to share:
Hello, I am the maker of the TetraMouse and I want to thank you for your story of the TetraMouse. The picture shown is one of the older models. New models come in color combinations of your choice in a new 3D printed, biodegradable housing made from PLA plastic, which is made from corn starch and is non-toxic. The new housing is no longer a boring black rectangular box, but is streamlined and shaped so it protects the joysticks from accidents like power wheelchair collisions. The new models can perform up to 10 mouse button/scroll functions on a Mac and up to 7 functions on a PC running Windows. Functions include left, right, middle, button 4, button 5, button 6, button 7 and button 8 clicks, scroll up, scroll down, and left and right click and hold. For more info see the TetraMouse.com website.