This dual beam photoelectric sensor provides the most advanced features in attractive, compact and weather resistant design. Features Twin synchronized pulsed beams provide greater stability and flexibility. It comes with a built-in viewfinders for optical axis adjustment and surge absorb circuit prevents the sensor from damaging by thunder. It is great for security system in school, office building, hospital, home yard, etc. DC 12-Volt up to 24-Volt. This device supports dual voltage. 12-Volt DC or AC 24-Volt/2 Amp in-line Power Supply is recommended.