This module uses a highly sensitive photosensitive resistance sensor. The comparator output signal is clean with good waveform and driving ability of more than than 15mA. With the adjustable potentiometer one can adjust the brightness of the light detected. The working voltage of the module is between 3.3V and 5V. The output format is a simple digital switching output (consisting of 0 and 1). Two bolt holes enables easy installation. It is a small board with a PCB size of 3.2cm x 1.4cm. Finally it uses a wide voltage LM393 comparator to drive the module. Depending on availability we stock either the four pin or three pin output version of the module - both have the same design and functionality.