•ThinkPad Travel Mouse (31P7410): 

•800 DPI optical sensor for precision control without dust-attracting mechanical ball 
•Programmable wheel for scrolling acts as a third button 
•Small size, lightweight 
•Ambidextrous design for right- and left-handers 
•Cable wrap to secure cable when traveling 
•1.22-meter (4.0-foot) cable with a USB connector 

Physical specifications:

◦Approximate weight: 72 g (0.2 lb) 
◦Approximate height: 29 mm (1.1 in) 
◦Approximate width: 52 mm (2.0 in) 
◦Approximate depth: 88 mm (3.5 in)