With retro-reflective sensors, the transmitter and receiver modules are contained in a single housing. The beam of light is returned to the receiver module by means of a reflector
. Objects are registered on account of the beam of light being interrupted. autosen’s retro-reflective sensors are available in an ultra-compact cuboidal form with a stainless steel housing, in a compact form with a plastic housing and with M12 and M18 threads in a stainless steel cylindrical form.