Miniature light barriers, W4S-3 Inox, WTB4S-3N2462V, switching distance max.: 4 mm ... 500 mm, sensor principle: reflection light sensor, detection principle: background suppression, switching output: NPN, switching type: light/dark switching, connection type: connector M12, 4-pin, light transmitter: PinPoint LED, setting: teach-in button, communication interface: -