Miniature light barriers, W4SL-3, WTB4SL-3P2261, switching distance max.: 25 mm ... 300 mm, sensor principle: reflection light sensor, detection principle: background suppression, switching output: PNP, switching type: light/dark switching, connection type: connector M8, 4-pin, light transmitter: laser, setting: potentiometer, laser class: 1, communication interface: -