CROSS-COMPUTER CONTROL - Game-changing capacity to navigate seamlessly on three computers, and copy-paste text, images, and files from one to the other using Logitech FLOW DUAL CONNECTIVITY - Use with up to three Windows or Mac computers via included Unifying receiver or Bluetooth Smart wireless technology ADVANCED ERGONOMIC DESIGN - Perfectly sculpted, hand-crafted shape supports your hand and wrist in a comfortable, natural position AUTO-SHIFT SCROLLING - Speed adaptive scroll wheel auto-shifts on the fly from click-to-click to hyper-fast scrolling RECHARGABLE BATTERY - Up to 70 days of power on a single charge.Wireless technology: Advanced 2.4 GHz wireless technology