standard optical mouse sm-312 (sm-312)

* Symmetrical shape,recess for thumb comfort hand
  * All kinds of injection color or rubber coating color available
  * Easy web navigation and scrolling wheel
  * Precision opticalsensor,super long working life
  * Interface USB,PS/2 and combo optional
  * Convenient for right hand or left hand users
  * Noiseless wheel while scrolling;small and lightest wheel mouse
  * Accruate on almost any work surface excluding transparent or highly reflective surface