特点
  profile as low as only 2.3mm.
 sharp index feedback is ensured by
     the metal contact structure employed.
  externally measures 10.0mm x
    10.0mm x2.3mm.
  reflow-solderable.
  4 way and center push operation
     are possible.

 应用范围
mobile telephones,vcr cameras,
     stereo headphones,car radios,
     pda,notebook pc.