Photoelectric sensors, GR18, GRL18S-F2338, Functional principle: Photoelectric retro-reflective sensor, Functional principle detail: With minimum distance to reflector (dual lens system), Switching output: PNP, Switching mode: Dark switching, Connection type: Connector M12, 3-pin, Light source: PinPoint LED, Adjustment: None, Communication interface: -, Included with delivery: Fastening nuts (2 x)