This part is a kind of semiconductor called LM356.
Function of this product has LOW Voltage Audio Power Amplifier.
Manufacturers : FCI
Image and pinout :
Some of the text within the PDF file :
The LM386 is a power amplifier designed for use in low voltage consumer applications. The gain is internally set to 20 to keep external part count low, but the addition of an external resistor and capacitor between pins 1 and 8 will increase the gain to any value up to 200. The inputs are ground referenced while the output is automatically biased to one half the supply voltage. The quiescent power drain is only 24 miliwatts when operating from a 6 volt supply, marking the LM386 ideal for battery operation. [ ... ]
LM356 PDF Datasheet Download