This part is a kind of semiconductor called 2SD1211.

Function of this product has Silicon NPN epitaxial planer type(For low-frequency amplification).

Manufacturers : Panasonic Semiconductor

Image and pinout :

Some of the text within the PDF file :

Transistor 2SD1211 Silicon NPN epitaxial planer type For low-frequency amplification Complementary to 2SB987 5.9± 0.2 Unit: mm 4.9± 0.2 s Features q q High collector to emitter voltage VCEO. Optimum for the driver-stage of a low-frequency and 40 to 60W output amplifier. (Ta=25˚C) Ratings 120 120 5 1 0.5 1 150 –55 ~ +150 Unit V V V A A W ˚C ˚C 1.27 0.45–0.1 +0.2 Parameter Collector to base voltage Collector to emitter voltage Emitter to base voltage Peak collector current Collector current Collector power dissipation Junction temperature Storage temperature Symbol VCBO VCEO VEBO ICP IC PC Tj Tstg 13.5± 0.5 s Absolute Maximum Ratings 2.54± 0.15 0.7–0.2 +0.3 0.7± 0.1 8.6± 0.2 0.45–0.1 1.27 +0.2 s Electrical Characteristics Parameter Collector to emitter volta [ ... ]

2SD1211 PDF Datasheet Download