The Siemens 3RH1921-1FA31 is a robust and reliable auxiliary contact block designed for optimal performance in a variety of industrial applications. This 4-pole attachable block features 3 Normally Open (NO) and 1 Normally Closed (NC) contacts, conforming to EN 50005 standards. With an insulation voltage rated at 690V and a surge voltage resistance rated at 6kV, it ensures safe and efficient operation. The part is designed to withstand ambient temperatures ranging from -25 to +60 degrees Celsius during operation and -55 to +80 degrees Celsius during storage. It boasts a mechanical service life of 10 million switching cycles and an electrical endurance of 200,000 switching cycles at AC-15 at 230V. The Siemens 3RH1921-1FA31 auxiliary contact block is part of the renowned SIRIUS product line, known for its high-quality and durable components.