Small light barriers, W12, WTB12-3P2431T01, device type: light sensors and light barriers, switching distance max.: 20 mm ... 350 mm, sensor principle: reflection light sensor, detection principle: background suppression, switching output: PNP, switching type: light/dark switching, connection type: connector M12, 4-pin, light transmitter: LED, light type: visible red light, setting: potentiometer