We have a front gate with pillars on both sides, each with a light fixture on top. We control those lights with one of these photoelectric sensors, allowing the lights to come on at dusk and go off at dawn. These devices last us about 6-8 years before they stop working. The device is constantly exposed to all weather, sun, rain, and other elemental conditions - we understand that nothing will last forever. We can tell when the sensor is not working when both lights do not turn on at night - if it is only one light, its probably the light bulb, but it would be almost for both light bulbs to burn out at the same exact time.
So anyway, our lights are not on at night, so we needed a new sensor. I got this as a replacement, and it looks exactly as the one we are replacing. It was easy to install - turn off electricity, remove old, put in new, twist caps, reseal, and test by putting a hat over the sensor lens. It works.
I am happy with this Photoelectric Sensor - it is an almost exact replacement for our old one, at a much better cost. I can stand behind this - it works, and has been working each night on our gate lights.