With a 35- by 62-millimeter footprint, Series 31 Opti-Vue photoelectric sensors are the company’s smallest photoelectric sensor line that offers a built-in SPDT relay with AC/DC models and 4-in-1 output with DC models. An integrated single pole, double throw (SPDT) relay eliminates the need for a separately mounted and wired relay, and 4-in-1 technology allows a single sensor to operate with four different output configurations, automatically selected by the sensor based on the connected load. The sensors have highly visible front status LEDs, ambient light immunity and an IP67 rated housing. Additional features such as potentiometer adjustment and universal mounting provide ease of setup and adjustment. Color-coded labels on the front of the housing allow for immediate identification of the sensing mode. Diffuse, retro-reflective, polarized retro-reflective and thru-beam models are available, each with a choice of a cable or quick disconnect.