[New Arrival-- New Version] 6D 2.4G Wireless Vertical Ergonomic Optical Mouse, 800 / 1200 /1600DPI, 6 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. RECHARGEABLE: This is a rechargeable unit. Requires no batteries, operating distance: 10m. USB connection, plug and play; Compatible with all versions of Windows OS, Mac OS X, Linux.Keylife: 5 million times