Ergonomic Design: The wireless vertical mouse places your hand in a natural grip position at a unique 60-degree angle to avoid forearm strain and will reduce muscle tension and protect your wrist. Efficient and Sensitive: Ergonomic mouse features 6 practical design buttons, plug and play; 800 1200 2400 3200 dpi adjustable mouse speed. Optical tracking technology has higher sensitivity than standard optical mouse for precise tracking on various surfaces. Silent Design: Wireless vertical mouse with silent button design, more suitable for libraries, bedrooms, offices, high-speed trains, and other public places. 2.4 GHz Wireless Connection: Wireless range is 10m; wireless receiver is plug and play for PC, laptop, and other devices. 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. We are well aware of how important customer service is to our customers, therefore we strive to provide the most thoughtful and prompt service. From order to delivery and handling customer service issues, we follow the entire process to ensure that your rights and interests are protected in the best possible way.