This part is a kind of semiconductor called GL5528.
Function of this product has (GL5516 - GL5549) Photoresistor.
Manufacturers : SENBA
Image and pinout :
Some of the text within the PDF file :
GL55 Series CdS Photoresistor Manual GL55 Series Photoresistor Photoresistor is a resistor which made of semi-conductor material,and the conductance changes with luminance variation .The photoresistor can be manufactured with different figures and illuminated area based on this characteristic.Photoresistor is widely used in many industries, such as toys,lamps,camera,etc. Schematic Drawing Performances and Features Coated with epoxy Small volume Fast response Good reliability High sensitivity Good spectrum characteristic Typical Applications Camera automatic photometry Indoor ray control Industrial control Light control lamp Photoelectric control Annunciator Light control switch Electronic toy Types and Specifications Specification Type GL5516 GL5528 Φ5 series GL5537-1 GL5537-2 GL553 [ ... ]