Cables4PC USB Black Mini Trackball Finger Mouse For Laptop/PC Retails for each is $39.95 This Finger Track Mouse is a brand-new input device. It is off-table, without limitation by operation space and avoiding harm to wrist and muscle. Best pointing device for Travel or Notebook. The two dimensions and buttons are simply controlled by fingers. The Track Mouse supports all kinds of interface to IBM/PC/XT/AT. ideal for free and comfortable operation. Can be operated in various ways to ensure long-term use without harm to AA wrist or muscle. User doesn't have to sit close to the monitor when using this mouse, AA reducing the harm of radiation and eye fatigue. X, Y dimensions can be controlled sensitively simply with the thumb. Compatible with Windows 3.1 and Windows 95/ME/2000/XP/NT