Logitech MK250 Compact Bluetooth Wireless Keyboard and Mouse Combo (920-013519) – Mouse Sensor Technology: Smooth optical tracking (1,000 DPI), Number of Buttons: 3 (Left/Right-click, Scroll-wheel with middle click), Battery life Mouse: 12 months, Battery Type; Mouse: Alkaline Battery, Keyboard: 12 months, Battery Type; keyboard: 2 x AAA (included), Wireless Operating Distance: 10 meters, Wireless technology: Bluetooth Low Energy Technology