Having a narrowly focused light beam, the Series 0507 of miniature rectangular sensors detects objects through holes and gaps, as well as closely lined-up or laterally approaching objects with distances that cannot be kept constant. The series is characterized by the small size of the sensors (5 by 7 millimeters), with a housing length of 40 millimeters. The spherical sapphire lens is scratch resistant and projects a virtually cylindrical light beam with a diameter of less than 4 millimeters, permitting vertical as well as horizontal mounting. The devices are short-circuit proof and operate in a voltage range of 10 to 30 VDC, and with an output current of up to 100 milliamperes. They are fully vacuum potted and, therefore, largely insensitive to environmental influences (IP 67).