Small light barriers, W12, WSE12-3N2431, Device type: Light sensors and light barriers, Max. switching distance: 0 m ... 20 m, Sensor principle: One-way light barrier, Switching output: NPN, Switching type: Light/dark switching, Connection type: M12 connector, 4-pin, Light transmitter: LED, Light type: Visible red light, Setting: Potentiometer, Included in delivery: 2 x clamp holder BEF-KH-W12, incl. screws