This part is a kind of semiconductor called MOC-3021.

Function of this product has 6-Pin DIP Random-Phase Optoisolators Triac Driver Output.

Manufacturers : Motorola

Image and pinout :

Some of the text within the PDF file :

MOTOROLA SEMICONDUCTOR TECHNICAL DATA Order this document by MOC3020/D GlobalOptoisolator™ 6-Pin DIP Random-Phase Optoisolators Triac Driver Output (400 Volts Peak) The MOC3020 Series consists of gallium arsenide infrared emitting diodes, optically coupled to a silicon bilateral switch. • To order devices that are tested and marked per VDE 0884 requirements, the suffix ”V” must be included at end of part number. VDE 0884 is a test option. They are designed for applications requiring isolated triac triggering. Recommended for 115/240 Vac(rms) Applications: • Solenoid/Valve Controls • Lamp Ballasts • Interfacing Microprocessors to 115 Vac Peripherals • Motor Controls MOC3021 MOC3022 MOC3023 * [IFT = 15 mA Max] [IFT = 10 mA Max] [IFT = 5 mA Max] *Motorola Preferred Device [ ... ]

MOC-3021 PDF Datasheet Download