[Upgraded Version] 5D 2.4G Wired Vertical Ergonomic Optical Mouse, 800 / 1200 /1600DPI, 5 Buttons - Black SCIENTIFIC ERGONOMIC DESIGN: Scientific ergonomic design encourages healthy neutral "handshake" wrist and arm positions for smoother movement and less overall strain. ADVANCED TRACKING TECHLONOGIES: 800 / 1200 / 1600DPI resolution optical tracking technology provides more sensitivity than standard optical mice for smooth and precise tracking on a wide range of surfaces. GREAT CONVENIENCE: Hidden nano receiver occupies minimum space; Added next / previous buttons provide convenience when webpage browsing; the best choice for internet surfers, gamers and people who work at length at the computer. EASY TO USE BUTTONS: All buttons are easily operable without contorting your fingers. The button force is light for easy clicking, but still firm enough to avoid accidental actuation. PACKAGE INCLUDES: 1 Porttu Vertical Ergonomic Optical Mouse (with 4.8 ft cable), 1 instruction manual. Includes 18 month warranty and lifetime technical support guarantee