A:Answer As stated in answers to other questions, and mentioned in the "What's included" section of the product description, there is customization software for that purpose. It appears that they call it "Logitech Options" now, and it is available from their support site. The button defaults are Forward and Back above your thumb, and Middle click on the scroll wheel click, and left or right when pressed those directions. Logitech states "7 Customizable Buttons" on the package back. To be clear, I only use the defaults, and I don't use the customization software, so I cannot tell you what options are available inside the software. The changes would also be specific to that computer, in that OS, you would have to make your changes to each computer and OS you wanted to use it with. ( while not very common anymore, some folks do have dual/multi boot computers, and you would have to customize for each OS ) Do be aware, the customization software from Logitech is only for Windows or Mac. While there are no customization options, the M705 Marathon mouse is plug and play with Linux, and if available for your Linux, there is the Solaar application which lets you configure the UniFying receivers and pairing of devices. The battery life on these is excellent, as I move one between three laptops currently and after probably 8 to 9 months of heavy use, it is still showing around 50% battery life.
