Solid-state relays (SSRs) are not a specific brand but a category of electronic switching devices used in industrial automation. They are produced by various companies worldwide, including Omron (Japan), Crydom (USA, a part of Sensata Technologies), and Panasonic (Japan). SSRs serve industries such as manufacturing, HVAC, and energy management by providing reliable, noiseless switching for electrical loads. Key products include AC/DC output SSRs, PCB-mounted SSRs, and DIN rail-mounted SSRs, known for their durability and fast response times.