The RZC1-04ZRS-KR0 is a reed switch-based sensor made by Sick. It is designed for high levels of protection against mechanical and environmental factors, with an IP68 rating for protection against dust, dirt, and water. It is also highly temperature resistant, with a range of -30 to 80°C. It has an output configuration of NO (normally open), meaning it is open in the absence of a magnetic field, and closed in the presence of one. This sensor is powered by a voltage supply of 5 to 30 volts DC.