The SICK WTB16I-24161120A00 is a W16-series photoelectric proximity sensor that uses an infrared LED to detect objects at distances from 10 mm out to 1.5 m. It's a straightforward presence-detection part for automated lines — packaging conveyors, material handling, assembly stations — where you need a reliable eye that doesn't need a reflector on the far side. The 20 mm wide housing fits standard 20 mm mounting brackets, and the M12 4-pin connector means you're swapping it in minutes, not re-terminating wires in a junction box.
IP66/IP67/IP69 is the headline here. IP69 means it takes 80 °C water at 80–100 bar from a pressure washer — the kind of washdown you see on food-and-beverage lines or in dairies. The infrared LED (not visible red) means you won't confuse the spot with a laser alignment tool, and it punches through dust and steam better than visible light. The 1.5 m max range is plenty for most conveyor presence checks, but if you need to see through a gap or detect a dark target, the 10 mm minimum range means you can mount it close without losing detection. Output flexibility is built in: NPN, PNP, or push-pull on the same four pins, selectable via the light-on/dark-on switching. That means one part number covers both sinking and sourcing PLC input cards — handy when you're stocking spares for mixed panels. The 100 mA load current handles most small relays or PLC inputs directly. Response time is 500 µs, which is fast enough for counting bottles on a line at moderate speeds but not so fast that it false-triggers on vibration. If you're running a high-speed pick-and-place, you'd want a faster sensor, but for most proximity work this is a solid middle ground.