Features: 1.Ergonomic Design: The wireless vertical mouse places your hand in a natural grip position at a unique angle of 60 degrees to avoid forearm sprains and will reduce muscle tension and protect your wrist. 2.Efficient and Sensitive: Ergonomic mouse has 6 practical design buttons, plug and play; 800 1200 2400 3200 dpi adjustable mouse movement speed. Optical tracking technology has higher sensitivity than standard optical mouse for accurate tracking of various surfaces. 3.Silent Design: Wireless vertical mouse with button silent design, more suitable for libraries, bedrooms, offices, high speed rail planes and other public places. 4.2.4 GHz Wireless Connection: Wireless range is 10m; wireless receiver is plug and play for PC, laptop and other devices. 5.System Support: For Windows 2000, for Windows XP, for Windows 7, for Windows Vista, for Windows 98, for OS, for Windows ME, for Windows 8, for Windows 10, etc. specification:Item Type: Wireless Vertical Mouse Product Material: ABS Number Of Keys: 6 Keys DPI: 800 1200 2400 3200 Battery: AA x 1 (Battery not Included) Mouse Size: Approx.140 x 75 x 80mm / 5.5 x 3 x 3.1in Receiver Size: Approx.6 x 19 x 14.6mm / 0.2 x 0.7 x 0.6in PackageList: 1 x Wireless Vertical Mouse 1 x Wireless Receiver