A4Tech Optical Wheel Mouse wired USB Model: OP-720 Black <br>
<ul>
<li>Upto 800 DPI</li>
<li>No tracking ball to clean</li>
<li>Precision Optical Sensor</li>
<li>Works on most surfaces</li>
</ul>
<br><br>System Requirements: Windows 2000/XP/2003/Vista/Windows7 &amp; 8