This part is a kind of semiconductor called GK152.
Function of this product has Single-beam infrared photoelectric sensor.
Manufacturers : EVERCOLORS
Image and pinout :

Some of the text within the PDF file :
GK152 GK152 ² TEL:020-84859506 84851526 FAX:020-84851726 http://www.everlight58.com E-mail:sales@evercolors.com [ ... ]
GK152 PDF Datasheet Download
