The Baumer FHDK 20P6901/S35A is a background suppression photoelectric sensor with a sensing distance ranging from 30 to 200 mm and a variable sensing range depending on the set distance. It features a pulsed red LED light source with a wavelength of 660 nm and a quick response time of less than 0.5 ms. The sensor is equipped with both green and yellow LED indicators for alignment and output status, respectively, and includes a teach-in method for distance adjustment. It supports a voltage supply range of 12 to 30 VDC and has a maximum current consumption of 48 mA. The output function can operate in light or dark conditions, and the sensor includes PNP output circuitry with a maximum output current of 100 mA. Safety features include short circuit and reverse polarity protection. The sensor's compact, rectangular design measures 20 mm in width, 42 mm in length, and 15 mm in depth, with a housing made of durable plastic (PBT-ASA) and a PMMA front optics. It offers an IP 67 protection class, making it suitable for harsh environments, and operates within a temperature range of -25 to +65 °C. The sensor also minimizes reciprocal influence and is equipped with an M8 4-pin connector for easy installation.