IO-Link - M21 modules are a product category under the IO-Link standard, primarily associated with industrial automation. These modules are manufactured by various global companies, including prominent German brands like Siemens and IFM, as well as other international players such as Balluff (Germany) and Pepperl+Fuchs (Germany). They serve industries like manufacturing, automotive, and logistics, enabling smart sensor and actuator communication in Industry 4.0 applications. Key products include M21-rated IO-Link masters, hubs, and device modules, designed for rugged environments with IP67 protection. These solutions streamline data exchange in industrial networks, supporting real-time monitoring and predictive maintenance.