Solid-state relays (SSRs) are not a specific brand but a category of electronic switching devices that use semiconductor components to switch power without mechanical parts. Various companies globally manufacture SSRs, including prominent brands like Omron (Japan), Crydom (USA, now part of Sensata Technologies), and Carlo Gavazzi (Switzerland). These relays are widely used in industrial automation, HVAC systems, medical equipment, and energy management due to their reliability, fast switching, and long lifespan. Key products include AC/DC output SSRs, PCB-mounted SSRs, and DIN rail-mounted SSRs, catering to diverse voltage and current requirements.