Anker 2.4G Wireless Vertical Ergonomic Optical Mouse, 800 / 1200 /1600DPI, 5 Buttons - Black Scientific ergonomic design encourages healthy neutral "handshake" wrist and arm positions for smoother movement and less overall strain. 800 / 1200 / 1600 DPI Resolution Optical Tracking Technology provides more sensitivity than standard optical mice for smooth and precise tracking on a wide range of surfaces. Added next/previous buttons provide convenience when webpage browsing; the superior choice for internet surfers, gamers and people who work at length at the computer. Enters power saving mode (power is cut off completely) after 8 minutes idle, press right or left button for it to wake. Product dimensions: 120*62.8*74.8 mm; product weight: 3.4 oz. Package includes: 1 Anker Wireless Vertical Ergonomic Optical Mouse (2 AAA batteries not included), 1 2.4G USB receiver , 1 instruction manual. 18-month hassle-free warranty.