This part is a kind of semiconductor called 4N35.

Function of this product has Optocoupler.

Manufacturers : Vishay Telefunken

Image and pinout :

Some of the text within the PDF file :

4N35, 4N36, 4N37 Vishay Semiconductors Optocoupler, Phototransistor Output, with Base Connection A1 C2 NC 3 6B 5C 4E 21842 i179004-5 DESCRIPTION Each optocoupler consists of gallium arsenide infrared LED and a silicon NPN phototransistor. AGENCY APPROVALS • Underwriters laboratory file no. E52744 • BSI: EN 60065:2002, EN 60950:2000 • FIMKO; EN 60065, EN 60335, EN 60950 certificate no. 25156 ORDER INFORMATION PART 4N35 4N36 4N37 FEATURES • Isolation test voltage 5000 VRMS • Interfaces with common logic families • Input-output coupling capacitance < 0.5 pF • Industry standard dual-in-line 6 pin package • Compliant to RoHS directive 2002/95/EC and in accordance to WEEE 2002/96/EC APPLICATIONS • AC mains detection • Reed relay driving • Switch mode power supply feed [ ... ]

4N35 PDF Datasheet Download