<ul><li>HP X7 Wired Mouse X-550, 1600 DPIMouse Features,1 : Plug and play, Ergonomic, Feel more comfortable, Effectively relieve the tiredness of the long time use.2 : Sensor Resolution 1600 DPI 800-1200-1600 DPI precision optical engine. Improve the ability of using the desktop control precision, agile.3 : A convenient and practical, press the wheel button can use auto scroll. 4 : Use as many as 10 million clicks life.5 : Number of buttons : Three Enjoy the comfortable HP Wired Mouse X550 with simple USB connection,</li></ul>