PHOTOELECTRIC SENSORSSA1U heavy-duty photoelectric sensors are offered in four sensing modes: through-beam, background suppression, diffuse and polarized retro-reflective. Long distance sensing ranges as far as 50 meters with through-beam models and as close as 1 meter with diffuse models also support 12-24 Vdc and 24-240 Vac. Sensors are UL/cUL listed, CE marked and IP67 rated.