Round light barriers, GR18 Inox, GRTE18S-P1112V, switching distance max.: 3 mm ... 115 mm, sensor principle: reflection light sensor, detection principle: energetic, switching output: PNP, switching type: light/dark switching, connection type: cable, 4-wire, 2 m, light transmitter: PinPoint LED, setting: potentiometer, communication interface: -, included in delivery: fastening nut (2 x)