The mouse has three buttons, one that works like a gun trigger that can work with your index or middle finger. The trigger button is a regular left click, the button on the top left is like a middle click and the one on the top right is a right click. Of course you can change these in windows to what you want. The trackball needs to be pushed down a little to work properly, but thats no big deal. Like all trackballs, you can remove it and clean it when its needed. These devices come with a USB or PS/2 connector. No CD came with the device, and it uses just regular mouse drivers. It claims its compatible with Windows 95 version B/98/ME/NT/2000/XP, I’ve only used it on XP though. It comes in handy for presentations or when you don’t want to use a regular mouse on the desk. One thing I’ve noticed is that the box design could use some better graphics and better spell checking, there were several typos on the box.