Miniature light barriers, W4SL-3H, WTB4SL-3P4162H, 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: cable, 4-wire, 2 m, light transmitter: laser, setting: teach-in button, laser class: 1