Logitech SIGNATURE M650. Upgrade your desktop settings for all-day comfort and efficiency. Upgraded for smarter scrolling, comfort and efficiency, the Signature M650 features SmartWheel scrolling, which provides precise positioning and speedy scrolling for your different needs. 1) Specifications and Details Specification Signature M650 Height: 108.2 mm Width: 61 mm Depth: 38.8 mm Weight: 101.4 grams Signature M650 L Height: 118.7 mm Width: 66.2 mm Depth: 42 mm Weight: 115.4 grams 2) Technical Specifications Sensor Technology Sensor Technology: Logitech Advanced Optical Tracking Technology Rated: 400 dpi Maximum: Up to 4000 3) Buttons Number of Keys: 5 (Left/Right, Back/Forward, Wheel that doubles as a center button) Customized Applications Powered by Logi Options+ for Windows and macOS 4) Battery Battery type: 1 AA battery (included) Battery life with Logi Bolt USB receiver: up to 24 months Battery life using Bluetooth: up to 20 months