A4Tech X-755BK

Specification: 
Number of keys: 6 +1 wheel button; 
Resolution: 500/800/1200/1600/2000 dpi; 
Interface: Adjustable USB: 125-250-500-1000 Hz (USB Full Speed); 
Frequency of processing frames: 6500 frames / sec.; 
Image Processing: 5.8 megapixels / sec.; 
Maximum speed: up to 1 m / s; 
Software: Windows 98/2000/2003/XP/MAC 8.6-10.X/Vista.