Logitech Signature M650 for Business Wireless Mouse - Medium Graphite (910-006274) – Sensor Technology: Logitech Advanced Optical Tracking, Nominal value: 400 dpi, Max value: Up to 4000, Number of Buttons: 5 (Left/Right-click, Back/Forward, Scroll-wheel with middle click), Battery type: 1 x AA battery, Battery life with Logi Bolt USB Receiver: up to 24-months, Battery life with Bluetooth: up to 20-months, Connection Type: Logi Bolt USB Receiver, Bluetooth Low Energy Technology, Wireless range: 10m wireless range