A4TECH Wired Mouse OP-330S, 1200DPI, 3 Silent Keys, Black Plug & Play wired mouse with 1200 DPI resolution and optical sensor. It has 3 silent keys, a scroll wheel on 4 sides and has a symmetrical design to suit both right-handed and left-handed users. It has a non-slip surface and stands out for its high durability (up to 5 million clicks). -high resolution 1200 DPI -quiet clicks -8 in 1 Gesture - washer with movement on 4 sides -symmetrical design for right-handed and left-handed users -Plug & Play function Specifications Type: Wired Ergonomic Design: Symmetrical Sensor: Optical Resolution: 1200 DPI Buttons No.: 3 Port: USB Cable length: 150 cm System Requirements: Windows 7 / 8 / 8.1 / 10