H&-sculpted comfort contour The perfectly sculpted, h&-crafted shape* of this comfort mouse supports your hand & wrist in a comfortable, natural position. Experience fine-motion control & fluid experience with well-positioned buttons & wheels. Unique scrolling experience Scroll through long documents or web pages faster & easier. The speed-adaptive scroll wheel auto-shifts from click-to-click to hyper-fast scroll. Experience side-to-side scrolling with a stroke of your thumb. To unlock the full range of thumb wheel possibilities, install Logitech Options™ software. Logitech Options™ software lets you customize those experiences. Darkfield Laser Tracking Darkfield™ Laser sensor tracks flawlessly virtually anywhere, even on glass* & high-gloss surfaces. Rechargeable battery Charge quickly. You can get enough power for a full day of usage in only 4 minutes, with no down time while recharging. A full charge can last up to 40 days*. When the battery gets low, an indicator light lets you know. Recharging is fast & easy. Just plug MX Master into your computer using the micro-USB charging cable. Continue using your mouse while it charges. Dual connectivity & Easy-Switch technology Connect this performance mouse via the included Logitech Unifying Receiver or Bluetooth Smart wireless technology. Thanks to Logitech Easy-Switch™ technology pair up to three devices & easily switch between them with the touch of a button.