Logitech Signature M650 2000 DPI Optical 5 Buttons Bluetooth Wireless Graphite Mouse Upgrade to smarter scrolling, better comfort, and more productivity. The Signature M650 features SmartWheel scrolling that delivers precision or speed the moment you need it. A choice of sizes for smaller, larger and left hands means there's a perfect fit for anyone. Seamless wireless connectivity, silent clicks, customizable side buttons, and the contoured shape keep you comfortable and productive hour after hour.