Kensington's SlimBlade Pro is all about keeping you pain-free. Its trackball reduces wrist movement, helping avoid repetitive strain injuries. You can still effortlessly scroll simply by twisting the dial. And no hand is left behind because its ambidextrous design fits both righties and lefties. And to help you get more done, you can use the KensingtonWorks software to program 8 sets of buttons - 4 individual and 4 combos. Good to know - Set your speed just right with 4 DPI levels - from precise editing at 400 to breezy browsing at 1600 - Use the KensingtonWorks software to change button functions to best suit through your workflow - Stay comfy and productive through long work days with the detachable wrist rest - Free yourself from cables by pairing with either 2.4 GHz wireless or Bluetooth - The battery should last you up to 4 months, and you can always use it wired- Optical tracking lets you navigate quickly and accurately