This part is a kind of semiconductor called 4N35GV.

Function of this product has Optocoupler with Phototransistor Output.

Manufacturers : Vishay Telefunken

Image and pinout :

Some of the text within the PDF file :

4N25(G)V/ 4N35(G)V Series Vishay Telefunken Optocoupler with Phototransistor Output Description The 4N25(G)V/ 4N35(G)V series consists of a phototransistor optically coupled to a gallium arsenide infrared-emitting diode in a 6-lead plastic dual inline package. The elements are mounted on one leadframe using a coplanar technique, providing a fixed distance between input and output for highest safety requirements. Applications Circuits for safe protective separation against electrical shock according to safety class II (reinforced isolation): 14827 D For appl. class I – IV at mains voltage ≤ 300 V D For appl. class I – III at mains voltage ≤ 600 V according to VDE 0884, table 2, suitable for: Switch-mode power supplies, line receiver, computer peripheral interface, microprocessor [ ... ]

4N35GV PDF Datasheet Download