G18-3B30NA Three Line DC NPN NO Output Photoelectric Sensor Switch with Reflector
Retroreflective type
Retroreflective type photoelectric switch also integrates the transmitter and the receiver, Its difference from other models is that reflecotr is used to relfect light to the photoelectric switch. Though the object between the photoelectric switch and reflector can reflect the light, it is much less efficient than the reflector so as to cut down reflected light.
