Small light barriers, W12, WL12G-3O2431S51, device type: light sensors and light barriers, switching distance max.: 0 m ... 4 m, sensor principle: reflection light barrier, detection principle: autocollimation, switching output: PNP, switching type: light/dark switching, connection type: M12 connector, 4-pin, light transmitter: LED, light type: visible red light, housing material: die-cast zinc, setting: potentiometer